Building a 350: newbie finer points? [Archive]

curtis73

10-03-2006, 08:49 AM

After reading some good posts here I have some final questions on a powerplant for my Baja 190 supersport. It currently has a wasted 305 and a good alpha so I'm replacing it with a 350. I know very little about I/Os, but I have a good bit of experience assembling engines so I thought I'd save some cash and build it myself instead of paying someone else $1300 for a shortblock... jeez that stuff is expensive.
Anyway, I'm shooting for 300 hp with a top RPM of 5000. I need to know some things before forging ahead. The dyno simulation below was made using desktop dyno with an off-the-shelf Comp 212/218 marine roller and as-cast vortec iron heads.
- Given the power curve, should I tune for 5000 rpm with out any load in the boat so I still have plenty of power at 4500 and up for the extra weight?
- Is my torque peak at an OK place? Will I be putting too much torque to the Alpha? Will I be on plane by 3000 ya think? That dyno simulation is with a roller cam... should I consider switching to a flat cam to bleed off some of that torque?
- Does a stock marine exhaust manifold flow better or worse than a typical stock automotive manifold? A little better? A lot better? A lot worse?
- I may buy a marine shortblock. If I do, what do I look for in a quality build? I know about brass freeze plugs. Do the crank, rods, pistons need to be forged? Are 4-bolt mains necessary, or just a benefit? What should I look for in the oiling system?
- I have a friend at a plating shop here in town and I already have an aluminum intake... can I just have my intake plated with brass or something? Do I need a marine intake?
- 90% of my boating is in fresh water. Can I get by with aluminum components during the 10% saltwater time? Is a cathoded piece of aluminum as good as an unprotected iron piece?
I know I ask many dumb newbie questions, but I gotta learn somewhere. I have some books coming that should reduce my number of questions.

SmokinLowriderSS

10-03-2006, 12:27 PM

I think you have a very good looking build there. Someone other than I will have to comment on the durability of a Merc Alpha drive. The torque pull sure should help holeshooting it onto plane, especially if you strap on a couple skiiers or a tube. You may also find you can pull several inches more prop and get better mileage (if you can keep your hand (throttle) out of it). :)
Usually in my simulations on DD, I run High-perf Manifold w/ mufflers, but I am usually hooking a big block up to log-manifolds on jet. I think that may still be more accurate, unless you are running thru-hub. Then, the stock may be more accurate.
I do know folks who have put the cutout systems on a small-block, and gained nothing so the hub-exhaust isn't to bad on the small motors.
A "marine" block is the same cast iron one in a car, usually just brass freeze plugs. The build parts inside depend entirely on how hard you are trying to work the engine. My 454 is making 400HP (loafing, i know), spinning a cast crank, and the engine builders here have no concerns for me unless I want to spin it up beyond 6-large (which I do not), even to 600 HP. It's a 2-bolt as well.
This 300 HP 350, if built with care, toleranced properly (IMO, factory stock tolerances, ABOVE THE MID-RANGE of each tolerance (ie, slightly "loose")), a cast crank if you have one should be fine, stock rods should be fine. Cheap insurance on the rods would be a set of ARP rod-bolts and a re-size on them. Forged pistons are not a must (my cast ones been running 28 years, even sipping 75HP of Nitrous), but, since a set of Speed-pro Powerforged's will set you back under $400, if you have the $$, and need pistons, why not upgrade for nearly nothing. A set of casts will cost likely over $300.
IF the boat sits in the lake, engine ful of water, all summer, you will have galvanic corosion problems with an Al intake. If it only sits all weekend, or maybe a week on a big holiday, then comes out to the trailer & sits dry 98% of it's life, you will have no trouble.
Salt water is a different issue.
Rinse the snot out of it, and rinse it some more, then rinse it again. There are helpful products out there, others must fill in here as I do not make it to oceans with Lowrider.
IMO, for 95% of the uses, the stock oiling system is plenty up to snuff, especially for a moderate build level. Put in a windage tray, a oversize pan is not a bad thing, but I ran 28 years so far on a stock-sized one (a larger one is in planning, but will be a while), stock pump too. As long as you get (and can maintain) 10psi per 1,000 RPM, you are OK. A long hard run will heat the iol, thinning it. If it is severe enough, a cooler will be needed. Depends a lot on how you drive. I've not been able to run more than 3 or 4 miles, flat out, and no issues, but I am also pushing my engine harder as I update things, and I am watching.
Clean out any flashing (casting excess) from the block drains before you have the block cleaned/clean it, this helps keep drain-back from being interfered with.

curtis73

10-03-2006, 03:58 PM

Excellent info!!! Thanks for such a complete response!
I was considering running cutouts to a transom exhaust just for sound :) I like the sound of it open, but heading up the lake at 5am to catch some bass might seriously tick off the rest of the campground :)
Good advice on the aluminum components. This boat was purchased mainly for the 2 months on the lake in the summer, then local lakes and maybe some salt on the weekends the rest of the year, so I'll stick with iron stuff. The 305 currently has an iron manifold that I could re-use, but aren't the newer ones aluminum with a plated water passage? What are they plated with, and can I just have my buddy electroplate an Edelbrock Performer?

Ryan00TJ

10-03-2006, 07:36 PM

Smokin is right on his is above post. Spinning to 5000rpm max will be fine with a cast setup. 2 bolt is fine, my current is an all cast Jasper shortblock 2 bolt. I spin it 5600rpms and 69mph w/ no problems. Your Alpha should also stay very healthy at that power level and rpm level. Just remember the Alpha does not like full throttle hole shots. Most problems with the drive revolve around an all out hole shot. When your up on plane have no worries hammering down. My Alpha has been going strong since 92 with some stout small blocks and 6500rpms.
My boat has always been in freshwater and sits May-Sept every year. I've used both Performer RPM and Victor Jr intakes with Felpro gaskets with no corrosion problems. 7 years on one setup was the longest. Key here is strictly freshwater. Salt is whole new ballgame.

SmokinLowriderSS

10-03-2006, 08:13 PM

Nobody runs plated passages in manifolds. In cars, the anti-corrosion additives in the coolant keep corrosion shut down. Same in salt water as you switch to closed loop cooling, anti-freeze, and a water to coolant heat exchanger.
Since you run an I/O, you already have anti-corrosion Zinks in place. Maintain them and use a good manifold like a Performer. The Zinks sacrifice themselves saving Alum parts like Drive housings, manifolds (intake & exhaust), Alum props, etc, from the Iron engines and Stainless prop shafts & hardware.
I think I took over 50 pounds off my boat pulling the iron dual-plane and replacing it with a Performer RPM Air Gap. First time I heaved on it, and it didn't move, I looked again to make sure I hadn't missed a bolt someplace. I just hadn't pulled hard enough. I'll swear it's at least 70 pounds.
When you bolt the intake down, LIGHTLY RTV the coolant passages on the intake gaskets, or they tend to leak, also retorque several times, at least 1 of them after first heat-cool cycle. If not, they will leak water soon, usually INTO the engine. Then you have an annoying mess to straighten out.
Also RTV the corners where the gaskets meet LIGHTLY, to avoid an oil leak here, same for the oil pan. Too much just becomes a mess inside the engine.
In fact, torque EVERYTHING that gets a torque spec at least 3 times, then check them again, tripple-check the bottom end a few more times, just to make certain nothing got missed before the pan goes on.
A buddy bough a jet boat with blown-up 460. I helped him dissassemble it. #8 rod UNSCREWED a con-rod nut, then threw the rod, ruined block, crank, pan, and 3 rods total (parts pin-balling arround). HAD to have been an improper torquing, either missed or insufficient. We found the side of the rod, still together (broken completely off the rod end), minus nut, and the undamaged nut, in the pan sump.
If you want to stiffen the 2-bolt lower end up a bit, cheaply, stud it. ARP set, roughly $50. Some folks think the mains need to be align-honed after, some do not. I fall in the not category since they are not aligned by the bolts like rods are but by the cuts in the block. You decide.
You don't need fancy for rings & bearings either. I was advised Clevite 77 bearings, and I am happy. Moly rings, I happened to get double-moly, same price. I have not seen much use of gapless rings, and some folks I know have seen very little, very specialized, good uses for them. I know others who swear by them. Seems to be ring flutter problems, aespecially double-gapless ring sets (gapless #2 compression). Personally, I have zero trouble with old-school standard rings, they work great and I am not trying to chase every 1/2HP there is.
There is a co-worker who swears they are better than the bread slicer, but then he told me I am loosing 30% of my available HP (no typo, thirty percent) by letting my engine run 120* WFO instead of 190 like his cars. His advice is now dubious and suspect.

curtis73

10-03-2006, 08:14 PM

SmokinLowriderSS

10-03-2006, 08:24 PM

Your Alpha should also stay very healthy at that power level and rpm level. Just remember the Alpha does not like full throttle hole shots. Most problems with the drive revolve around an all out hole shot. When your up on plane have no worries hammering down. My Alpha has been going strong since 92 with some stout small blocks and 6500rpms.
Yes, and the power used to pull a skiier (or even 2) isn't usually what you use trying to beat some low-slung big-block jet onto plane. Pulling a skiier you more "roll quickly" into about 3/4 throttle or so, not a slam from idle to full. From what I have read, I understand it's the upper gearset that gets unhappy with lotsa torque applied too harshly to it. On plane, not a problem to wind it out. You will get a problem I do not, which is drive oil heating, keep an eye on that, you MAY need a drive shower if you tend to go a long ways pretty hard and get it hot. The big boys with big engines NEED them, badly, often on stock 496/502's & bravo drives.

SmokinLowriderSS

10-03-2006, 08:39 PM

Great. I just put in a bid on a cam on Ebay. Its listed as a NIB Melling marine flat cam for chevy. It specs out to 202/213 on a 110 LSA (ground 2* retarded) with just over .4" lift. I simulated 1.6:1 rockers for a little help and the dyno simulation spit out:
-301 hp @ 5000 using "h.p. manifolds" in the simulation
-285 hp @ 5000 using "stock manifolds" in the simulation
*mumbling to myself* Let's see, 2175 lbs for the bare boat, 230 for my fat butt, a little gas, guessing 2600 lbs, carry the 4, 10% loss through the outdrive for 257-270 hp at the prop, 10% prop slip***
yehaw!!! I'm knocking on 70 mph either way. That makes me happy. :rollside: I really wanted a roller cam and I might still do it for the sake of those long months when it sits letting the lobes dry out, but I'm perfectly happy with those numbers.
Those "long months", really shouldn't hurt anything. My Taylor, dad's boat, he bought new, sat, sometimes a couple YEARS between trips near the end of his ownership. She was spun enough getting her started every time that she never was "started dry" oil-wise. The cam was perfectly fine when I took it out 2 winters ago, lifters too. Just tossed tho, nobody was going to want a BBC cam specing .480"/.472". :cry: Heck, I'm still pretty mild at .565". :cool:
Again, personal preference here, but I'd prefer to buy a new cam, kit style, with springs included, all to fit together. This way I know the condition. If you buy that one, I hope it isn't worn badly. If you are unsure what to look for on the lobes, get advice from a pro somewhere. My buddy's in the 460, is about 1/2 shot, from likely a poor break-in procedure, which surprises neither of us as we know the prev owner of the boat, who likely rebuilt the engine itself (threw the rod at about 10 hrs). Probably short-sheeted the cam break-in too. If the cam is good, I'd prob buy new lifters, and re-break it in, just for peace of mind. Did the seller get the lifters all marked correctly? Who knows, hope so. Get one on the wrong lobe, it's all screwed.

curtis73

10-03-2006, 09:40 PM

If the cam is good, I'd prob buy new lifters, and re-break it in, just for peace of mind. Did the seller get the lifters all marked correctly? Who knows, hope so. Get one on the wrong lobe, it's all screwed.
Actually its a new in the box cam, but thanks. I don't re-use my own cams or lifters, let alone anyone else's :)
My concern with dry lobes is that lifters today (and today's oil... long story so I won't go into it) don't let lifters last nearly as long as they should. The problem is, any movement of the flat lifters on the lobes while they're "dry" can score the lobes. Since cam lobes rely entirely on oil slung from the crankshaft, no amount of priming the oil will prevent cam lobe failure on an engine with "dry" lobes.
I agree, its not much of an issue in the real world, but I deal specifically with a lot of low-mileage classic cars. I have a 73 Chevy that I bought with 58,000 miles and it had sat for three years. The seller primed the oil and started it and it was only a matter of 200 miles until I had three flat lobes for the same reason. I guess my line of work just rubs my nose in flattened cams day after day so I'm a bit paranoid :)
There are methods where you can drill a .010 hole in the base of the lifter to positively oil the lobes and that might be something to try. At least that way spinning the pump would put oil on the lobes. I've also toyed with the idea of using a piece of stainless brake line tubing with 16 holes drilled in it and install it above the cam. Bend it up at the back and drill a hole up through the intake for it to pass through. Then oiling the cam is as easy as squirting from an oil can. Just pressurize that little manifold and you're set. I come up with weird ideas like that all the time. I would have made a great Amish Farmer.
Oh.. and definitely a drive shower. I'm an ounce-of-prevention kinda guy
I'm really liking this dialogue and I'm learning soooo much. Thanks!!!!

curtis73

10-04-2006, 03:14 PM

By the way... I just won the cam for $33. :) Now, does anyone have a 350 block for me? I just missed a 4-bolt block on Craigslist for free :(

SmokinLowriderSS

10-04-2006, 04:17 PM

I think I may have an old oil pan laying out at dad's farm someplace .... :idea:

mtnrat

10-04-2006, 07:22 PM

I am also researching for a very similar build for a 18 foot deep V. I have a 350 marine FWC with only 20 hours :)
Known specs are:
crankshaft type - reground/polished cast crank
piston type - Sealed Power cast/dish pistons
camshaft specs -
intake duration is 202 @ 50
exhaust duration is 212 @ 50
intake camlift is 393
exhaust camlift is 408
110 degree lobe seperation
valve specs - 1.94 (intake) + 1.50 (exhaust)
compression ratio - 8:1
A low performance combo for sure.
I am looking at going all roller with vortec heads. I am considering the same cam(XR264HR-10) or may go a little smaller with the XR258HR-10 which seems to have a little better torque curve fromm 2000 to 2500. (I pull skiers quite a bit).
This is going to be a winter project and I hope to get 60mph out of her. I can get 50+ with the current set up.
I will find the current compression ratio and see how that will change with new vortec heads and proper quench. I also found a copy of "Small-Block Chevy Marine Performance: Engine Modifications for Maximum Boating Performance" by Dennis Moore that should help me with many decisions. Should be here on Friday :) :) .
I will be checking here to see how curtis73 build goes.
Let the fun and games begin!

curtis73

10-04-2006, 10:15 PM

I think I may have an old oil pan laying out at dad's farm someplace .... :idea:
I have the one on the 305, but I don't know how big it is. I figure I can scrounge a few external parts from the 305 like maybe manifolds, alternator, starter, PS pump, etc, but the dipstick has water on it and its rusty. I can't count on a crank, rods, anything out of that one.
I'm going to see a used 350 four-bolt long block tomorrow. The guy doesn't know anything about it so I'll take my bore gauge and do some poking around. He's asking $300 which is a deal if its good. I also found that my favorite machine shop in town sells a shortblock for $1200 and no core charge. I can give him my cam and ask for brass freeze plugs. That's not a bad deal.
mtnrat; I plugged in your cam specs on the 202/212 cam and it should be good for a strong 250 hp at 4750 rpm and that's simulating 8:1 with non-vortec heads. At that lift, vortecs won't offer too much benefit anyway, but if you swap to vortecs with some 1.6:1 rockers and bump compression to 9:1 you're at the same basic 300 hp I'm showing. Basically with those cams, the vortecs and 1.6 rockers are worth about a total of 25 hp and the extra compression is worth another 25 as well. I'll have some time tomorrow I'll plug in your comp cams to see how they do.

SmokinLowriderSS

10-05-2006, 05:07 AM

Just be careful on the shortblock. As I said earlier, since boat engines usually both run cooler than a car engine, yet also are pushed much harder, you get into situations such as a relatively cool block & cylinders with very hot or rapidly heated pistons. If the ring eng gaps are to tight, they can close up, very bad. If the bearing tolerances are to close, you can wipe one (or more), very bad. If the pistons are too snug with the cylinders, you can seize one, same story, not good.
If it was assembled "average", with all the tolerances about mid-range, it'd be fine. The trouble happens when one is set up "tight" , for supposed longevity, which is OK for a thermostated car, seldom puishing the engine all that hard, the boat engine is different.
I was kidding on the pan, it's been outside since about 1986. :yuk:

mtnrat

10-05-2006, 02:48 PM

curtis73, if I had enough high end torque to get to 4750 that would be great, but that is the problem. With a 14x21 I can get 4400rpm and about 50mph. It gets there pretty fast but quickly levels off. I have 14x23 that gets 53mph at 4200 rpm and would like to spin that at 4600-4800.
I know the lift is low and want to change the cam along with the heads.
You suggest changing to 1.6:1 rockers and to bump compression. With my current stock heads I get 8:1, and I know that the vortecks have smaller chambers, any guess on the compression with vortecs. And by bumping compression do you mean by changing pistons or the increase I will get by changing heads? From what I understand increasing lift is better done by changing cams rather than just changing rockers. I would like to retrofit a complete roller system.
Thanks

SmokinLowriderSS

10-05-2006, 03:12 PM

mtnrat,
I put a set of L-31 vortech iron heads on the Dyno simulation, and am curently running a cam build iteration to find ya the best torque. Will post ya the engine/cam specs when it's done ..... done running 13 million plus engine builds. LOL
Oh, based it with a 600 carb/FI and a dual plane manifold, guessing at what you have. Give me a better list of details like casting nunbers on heads and I can get more accurate.
13,323,310 tests setups. Lotsa cam range specs in there. This may take a few hours. :crossx:
The early runs are putting out 420-430 pounds, peaking arround 3500, trying to get a build that doesn't drop like a stone afterward. If it'll hold a solid, fairly flat torque curve, the HP will be there at 5K to help ya out.

mtnrat

10-05-2006, 04:59 PM

Wow. Yep dual plane performer intake and 4bbl carb. I do not own the heads yet but the casting numbers will be 12558062 or 10239906.

curtis73

10-05-2006, 05:01 PM

More later, but I just picked up a 350 4-bolt block with 10,000 on a 30-over. No ridge on the cylinders and the pistons look to have about the right dish for 9:1. The heads are 624s... don't know anything about them, but the block looks to be in killer shape.
Long block for $250 with no ridge? Yep, I scored. I had a cigarette after that one.

mtnrat

10-05-2006, 06:58 PM

SmokinLowriderSS

10-05-2006, 08:08 PM

dAMN, I think I used a few too many parameters, 5 hrs and 7% done. See ya Saturday. LOL

mtnrat

10-05-2006, 09:02 PM

:rollside: :)

curtis73

10-05-2006, 10:05 PM

You suggest changing to 1.6:1 rockers and to bump compression. With my current stock heads I get 8:1, and I know that the vortecks have smaller chambers, any guess on the compression with vortecs. And by bumping compression do you mean by changing pistons or the increase I will get by changing heads? From what I understand increasing lift is better done by changing cams rather than just changing rockers. I would like to retrofit a complete roller system.
Thanks
I agree that changing lift is better done with cam lobe lift, but most manufacturers only offer one lift in the duration you want. Using rocker ratio is a perfectly fine way of playing around with lift within a certain cam spec without having to search for another cam. But, since you're putting in a new cam anyway you might find one with a combination of duration and lift you seek. My small block math is pretty rusty, but I think on a 350, you get one full point for about 13cc???? So if you had a 76 cc head and swapped to the vortecs with 64 you will probably be smack on 9:1
And thanks for the link!!! I'll have to get rid of those heads discreetly. HEEEYYY! I don't have an anchor for the boat yet... maybe they'll do :)

curtis73

10-05-2006, 11:28 PM

SmokinLowriderSS

10-06-2006, 05:34 AM

By the way... I just won the cam for $33. :) Now, does anyone have a 350 block for me? I just missed a 4-bolt block on Craigslist for free :(
You likely already know this then from your experience, nut just in case, I've seen a lot of folks kill bigger flat-tappet cams on break-in. When I broke mine in I was given advice I call good, and had zero trouble.
IF you have multi-piece springs, leave the inner spring out to lower the spring pressures for the break-un & first 8 to 10 hrs of running. It really eases the pressure on the metal surfaces, that and GM EOS in the oil for more hi-stress lubricity. I had not heard aboput the EOS, but I had an oil pan full of fresh (just switched to) Syntech synthetic, and had zero trouble using it (kinda pricey but was last run of the year & storage planned anyhow).
I was also told by my source that he has seen more cam break-ins go sour on synthetic BLEND oil than either 100% either way (synthetic or dyno) and so advised against that. A lot of folks on here swear my Rotella diesel oil for break-in, ya can't really do the engine any harm running it daily either, it's a much higher stress spec oil for severe service diesel use than the worst of the gasoline specs.
I restarted the cam run just set at 9.6:1 (had a span of comp ratios in there too), got t6he list down to under 2 million, and it is almost done. Will post results with corrected heads soon.

SmokinLowriderSS

10-06-2006, 06:16 AM

This should help you ID the heads: http://www.thedirtforum.com/castings.htm
Casting # Years Valve size hp level Chamber Size/notes
462624 76-87 1.94/1.50 & 2.02/1.60 Not listed 76 CC Chambers
These are crack prone!
You are going to vortec heads anyway. looks like a great find.
Another good site:
http://www.mortec.com
Lots of GM and Holley references, well organized I think.
462624.....75-86...350/400......76cc chamber, 1.72/1.5, 1.94/1.5 or 2.02/1.6 valves
OK, here's the damage, best iteration is in ..... 9.6:!, L-31 Iron Vortech heads ... 1.94"/1.50" valves.
Torque peak is 446@3,000 RPM .... from there it looks like this:
3,000 ... 446 ... 255
3,500 ... 437 ... 292
4,000 ... 425 ... 323
4,500 ... 410 ... 352
5,000 ... 386 ... 367
5,500 ... 361 ... 378
The cam was as follows:
Roller, masurements at .050"
lift .450" both
Inake Duration, 202*
Exhaust Duration, 212*
IVO: -8
IVC: 30
EVO: 32
EVC: 0
lobe centerline, 107.5*
intake centerline 109*

mtnrat

10-06-2006, 06:40 AM

Thanks, I will look deeper into the numbers when I get a little time this weekend.

SmokinLowriderSS

10-06-2006, 06:43 AM

I thought of a few more questions:
- in my piston selection, I can get close to my target 9:1, but of course not exact. Since marine engines tend to run cool, how much compression can I realistically get away with on 87 octane? I don't need to be pushing the envelope, but if (for example) my choices are 8.75:1 with piston A or 9.23:1 with piston B it would be nice to know the practical limit. We know my cam is a short duration, and the boat is probably going to be somewhere north of 2600 lbs most of the time.
IF your new heads come out with 63cc chambers,
IF your pistons come up flush with the deck,
IF you run a .039" thick gasket (nothing wrong with a good Fel-Pro blue),
IF you do a .040" overbore
You need 28cc dish in the pistons to get 9.05:1
22cc for 9.57:1
17cc's gets you to 10.05:1, run premium & enjoy the extra 10 HP over 9.6.
Any differences to the above, needs to be recalculated. Gonna be some mock-up time here ,,, find out with the crank, rod, and an old piston the deck height flushness (liberally grease up a set of old bearings for the mock-up, should hold pretty decently centered, enough to be close enough, just do 1 cyl, don't really need rings on it IMO, for this check. Could use an old set tho.)
- The engine I just got today is a truck block, so it has the left side dipstick and the oil pan rail has a little curve in it. Any problem using the automotive oil pan on this since my 305's pan probably won't fit? It at least has a pathetic windage tray :)
Try It and see if it fits. I would think the pan rails would be the same. Make sure you get proper clearance to the oil pick-up, Play-doh works great here. :)
- Are there any special considerations for any of the gaskets that need to be made? If this were for a car, I'd just call and order the FelPro kit. Are copper exhaust and head gaskets out of the question due to corrosion? Are standard FelPro blue line gaskets OK?
No special considerations IMO. Fel-Pro's are good gaskets. A little RTV at the right places to prevent water & oil leaks, just like on a car.
- when I pull the exhaust manifolds off the old 305, how do I tell if they're good to use again? I read about a muriatic acid bath to clean off the scale, but how do I know if they're good? The main reason I ask is because I've been looking on Ebay for new ones, but almost all of them are the center outlet. Mine exit on top clear at the back. Since I seem to have trouble finding more rear-exit manifolds, keeping the old ones seems more important.
Don't know, sorry.
I can't tell you how happy I am with this new engine. I pulled the pan and heads and it looks VERY nice. Its dirty from sitting a few years, but bone dry and clean. I had expected $300 for the engine and $630 for machine work. I ended up buying the engine for $250 and now it looks like I can get away with a hot tank, a bottle brush hone, a magnaflux, and re-assembly. What I'm saving in machine work I can use to buy brand new Vortec heads. The guy even threw in a set of 40-over pistons for the next build, a flexplate, TC cover, balancer, crank pulley, and a wooden engine crate. God, I love Craigslist.
Congrats. :)

Aluminum Squirt

10-06-2006, 09:23 AM

curtis73

10-06-2006, 11:41 AM

Thanks for all the break in tips, guys and the answers to all my questions. I'm going down today to tear apart the 350 and I'll take the parts to the machine shop.

mtnrat

10-06-2006, 02:15 PM

What heads would you go with? I have a closed cooling system.

SmokinLowriderSS

10-06-2006, 03:07 PM

Hey smokin', I too will be building a SBC, hopefully soon, and I want an opinion. You mentioned some break in proceudres. I was always led to believe that breaking in with synthetic is a no no because its too slick and the rings would never seat properly. Is that an old wives tale that's not applicable with modern machining practices? Did I make this up or has nanybody else heard this? I'm going to run a roller cam/lifters so I shouldn't have any cam break in issues and everything I'm hearing is that old school break in of a motor doesn't really apply anymore. Break the cam in (if applicaple), put the motor through a couple of heat cycles, change oil a couple of times, re-torque everything, and drive it like you stole it-Aluminum Squirt
Well A.S, I have heard similar from "old hands" but unfortunately haven't polled anyone really on it.
I do have some oil usage on the 454, but, she's still really a young engine IMO (only arround 30 hours) and I suffered a major leakage this summer (oil filter got loose)so I really cannot define just how bad it is. It is looking initialy like about a quart over about 20 hours of run time, but don't score that as very accurate. I have no smoking or exhaust residue from it, just oil "vanishing" ...... It could easilly be vapor going up the un-baffled PVC and being burned there. I had some oil usage before the motor was rebuilt, a similar time frame, and not leakage
I have read where today's bore finishes are far smoother than they were 20 years ago and thus ring seal is almost immediate.
The folowing is stuff I have dug up for ya AS,
From Mobil-1's website FAQ area ....
Is it true that new engines need a break-in period using conventional motor oil?
That is a myth. In the past, engine break-in was necessary to remove any metal flashing (called swarf) or abrasive material left inside the engine after machining, as well as to allow the valves and rings to seat properly. Todays engines are built with much tighter tolerances, much improved machining and under much cleaner conditions compared to the engines of 10 or 20 years ago. Current engine-manufacturing technology does not require a break-in period using petroleum-based motor oils.
In fact, Mobil 1 has shown excellent results in industry-standard ASTM tests, most of which use completely rebuilt engines for each new test run. Mobil 1s outstanding results in these tests demonstrate that proper break-in using Mobil 1 is not a concern. Mobil 1 can be used in an engine from the day you drive off the showroom floor.
Can I use Mobil 1 as a break-in oil for a rebuilt engine?
Yes, but the timing of your first oil change will depend largely on the quality of the rebuild. Due to the tighter tolerances and improved machining of todays engines, the traditional concept of engine break-in is not as critical. However, if the engine rebuilder is using older machining equipment or lower-quality components, abrasive material can be left inside the engine. In this case, you should use a short drain interval on your initial oil fill.
From elsewhere:
CathKen Enterprises:
COMMON QUESTION AMONG NEW VEHICLE OWNERS is about the effect of synthetic oil on engine break in. Many dealers, mechanics and owners recommend against using synthetic oil during break-in. They accept the myth that an engine does not break-in properly when using synthetic oil. When questioned about this belief, most reply that synthetic oil is to slippery and does not allow the moving metal parts to seat themselves against one another.
This is simply not true; one of the very best things one can do for a new engine is to fill it with high quality synthetic oil before it runs the first time. A half century ago, car and motorcycle engines needed significant break-in time and care if they were going to give relatively long and reliable service. This fact of motoring life was mainly due to the roughness of the finishes on the parts that had to work close together. Piston rings and cylinder walls, for example, were not as precise or smooth as they now are. It is this roughness that requires break-in.
There is more of the same out on the internet, I'm trying to find stuff not from the oil makers or dealers, but is hard to.
Personally, I don't think I have a problem, and I don't think you will.

curtis73

10-06-2006, 03:25 PM

Scrap the vortec heads. for the same $ you can get something a whole lot better. The iron vortecs on a boat with open cooling are no better than the 624 casting for durabilty or performance.
Not disagreeing with you, but can you explain why? The vortecs flow over 20% more with the same port size.

FASTRAT

10-06-2006, 06:11 PM

Not disagreeing with you, but can you explain why? The vortecs flow over 20% more with the same port size.
well...time for my .02 cents...i "totally" agree...scrap the Vortec heads...look for an early set of FI heads (2.02x1.60) 64cc...chg the int's to 2.05, do a little (mild) port work, port the exh a little to match the ex manif's & match the intake ports to the manuf...also...chit can ur present int manif & look for an EB RPM Air Gap (they work great on BBC, ask Smoke about that!, so should/will work great on SBC)...u can hot tank the ex manif or sand blast them to almost new condition...as far as ur build goes...if it were me, i would have taken the 305 block & put a 383 stroker kit in it (more torque than u can believe!)...just my suggestions
fastrat
p.s. AS...the 383 might be the way to go for ur build!!!

curtis73

10-06-2006, 10:28 PM

well...time for my .02 cents...i "totally" agree...scrap the Vortec heads...look for an early set of FI heads (2.02x1.60) 64cc...chg the int's to 2.05, do a little (mild) port work, port the exh a little to match the ex manif's & match the intake ports to the manuf...also...chit can ur present int manif & look for an EB RPM Air Gap (they work great on BBC, ask Smoke about that!, so should/will work great on SBC)...u can hot tank the ex manif or sand blast them to almost new condition...as far as ur build goes...if it were me, i would have taken the 305 block & put a 383 stroker kit in it (more torque than u can believe!)...just my suggestions
fastrat
p.s. AS...the 383 might be the way to go for ur build!!!
Again, not disagreeing, but some of this goes against everything I know about engine building, but like I said.. I've never built one for marine engines. Just wondering why some of this would work better.
I'm only revving to 5000 and only making 300 hp, so is there a specific reason why the RPM manifold is a better match? It shines at higher RPMs that I'll never see. Same thing with the heavily modified heads; why spend thousands modifying heads beyond where I need flow, when I can put a brand new set of good vortecs on for $400 that more than suit the need?
The 305 can't become a 383. Its not possible because of the very small bore on the 305. 383s come from taking a 350 30-over and using a 3.75" crank. Also, my 305 is wasted... as in the oil pan has been sitting full of water for 5 years. There is nothing salvageable from inside that engine except maybe a pushrod or two :)
Again, not disagreeing since I know nothing about marine engines, I'm just wondering why I should scrap vortec heads that flow 240 cfms in favor of heads that flow 211 cfms, then sink hundreds into larger valves and porting to get them to flow 270 cfms? I think the vortecs are not only PERFECTLY matched to this build, but also a hard-to-beat bargain at $250-300 for a rebuilt set. If there is a compelling reason that I'm not seeing in the marine application I'll do it, but I'm getting confused.

Aluminum Squirt

10-07-2006, 01:59 AM

Hey Smokin, good info, thanx. Its taking me awhile to digest some of these new break in procedures. I guess I'm stubborn. I see perefect examples of zero break in at work everyday and the cars go 100,000 miles every time w/o hardly any problems. Anyway, thanx for the info. My build is probably going to be pretty slow so I'll have plenty of time to formulate what approach I'm going to take.
Curtis73, I can't comment very intelligently on flow characteristics of different heads, but I would tend to agree with the porting recommendation. At your performance level, there is a significant amount of HP waiting to be released by doing some porting and port matching. I'm not talking about spending $100's here either (isn't there a sticky topic around here about head porting???). Anyway, with some simple head porting and port matching there should be some pretty good HP in there. You don't have to get crazy, just be conservative, clean the bowls up, take out some of the casting flash, port match to your gaskets, etc. May as well clean up the oil drain back holes while you are there. Most of this can be done with 5-10 hours of careful work, a little bit of planning, and a few dollars in grind stones, sanding drums etc for your drill or dremel-Aluminum Squirt

mtnrat

10-07-2006, 06:12 AM

curtis73, I am going with the performer manifold which is designed for torque at low rpms and off idle. I also think the vortec heads are a good match for our application although I am looking at a conservative porting and port matching as Aluminium Squirt suggests. Not difficult and some extra ponies for 2-3 evenings work.
I am not sold on the 383 with what we are doing. I am not sure the cost is worth it. For my build the 350, vortecs and roller retrofit will give me as much or more power than my hull size and shape can handle. Pic attatched.

mtnrat

10-07-2006, 06:35 AM

I am looking at a set of NEW GM vortec heads with these specs.
-1.940"/1.500" Stainless High Flow Valves
-Hi Performance Springs Good To (.500 lift)
-PC seals
-Hardened Locks,Retainers and Seats
-5 Angle Valve Job
-CBN Finished Deck
-3/8" Studs
-Fully Machined For High Lift Up To .550" lift
Looks good for my application?

curtis73

10-07-2006, 08:50 AM

I'll show you why I don't need a 383. Take a look at the dyno charts. These are the absolutely exact same motors, but I just changed the stroke to make it a 383. Same exact 300 hp, but it peaks 250 RPMs lower. First of all, I have an Alpha which doesn't like more than 300, especially with as much skiing duty this boat might see. Secondly, its a 2600-lb 19' boat that doesn't need the extra holeshot torque especially with the alpha.
So why would I double the cost of this project to get power I neither want nor need?
I'll also answer the roller question for myself (even though I'm going with a flat). As an automotive engine builder for years now, I see the advantages of rollers and they are undeniable. Faster ramp profiles, much longer life, more area under the curve, less friction, longer oil life, better at dry startup after sitting winterized for 5 months, more usable torque, broader hp curves... need I go on? Even just for peace of mind and reduced friction are enough reason for me. Flat tappet cams are technology from the 1920s that was almost fully replaced in the 80s by either rollers or OHC, so while flats are still viable, I think its safe to say that in almost every way, rollers are better even if they didn't offer any more power.
I TRULY appreciate the suggestions, but I think we're getting a little off the spirit of its original intention. Since I'm building this engine myself and it really only needs a hot tank and re-assembly, total cost to buy AND build the shortblock will be under $400, plus I have a spare set of new pistons and used heads that I can sell on Ebay to recoup some of the costs. A 383 requires a crank, rods, and pistons and the cheapest kits I've seen are $638 for chinese castings that often require journal polishing before you can use them. Not that I couldn't buy it, but I don't wanna buy it since my projected power curve looks perfect as-is.
- I'm looking for 285-310 hp MAX, which is why I chose the Vortecs. They flow 230-240 cfm intake out of the box, have far superior chamber designs, and they're cheap even new.
- While I agree that porting is a GREAT way to get optimum power from the least port volume, what you have suggested is to buy heads that flow 210 cfms and then port them for more. While I agree that's a great idea for higher power, I already have a head choice that will meet my goals as-cast.
- Again, I have to ask why an RPM??? The performer's powerband is matched EXACTLY to my power band. Why would I buy an intake that sacrifices a few lb-ft down low only to add a few HP at 5500 rpm... which I'll never see? In effect I'll be giving up power... period. This isn't a race boat, its a performance pleasure cruiser that will absolutely max out at no more than 5000.
You have to understand that my last two boats were a 1958 Sea King 14' runabout with a 25-horse merc and a 1968 Glassmaster Tri-hull with a Merc 70. Now I'm talking about 300 hp and 70 mph in a 19' baja, so for now I think I'll be happy with what I have and there is plenty of room to grow. A small cam swap with those vortecs can take me to 350 real easy. Then maybe port the vortecs and I'm suddenly at 400.
Anyway, here's a quick screen cap of why I personally don't need a 383

curtis73

10-07-2006, 09:00 AM

Here's the boat that's getting my 350, mtnrat:

curtis73

10-07-2006, 09:59 AM

You are building a stock motor. You now have a short block....before you didn't. If you had to do a bottom end it is the same price to do either the 383 or a 350. I can buy a kit for the same price that it would cost me to have the machine work done
Ahh... I see. Read what I wrote, I don't need $600 of machine work. I need $150 worth of hot tank, lifters, and bearings. The shortblock is just dirty from sitting 5 years, not in need of a rebuild.
No arguements over the advantage of a roller set-up but you seemed to be concerned over $ spent so at the 285 to 300 hp level why waste the $
Which is why I'm using a flat. I was defending mtnrat's choice of roller
I can buy Darts here for the same $ as the vortecs and they will stand up better and make more power with no other changes
You can get new darts for $400 a pair assembled? Normally they're somewhere north of $1000. I'll take four :) My problem with the dart S/S OR the iron eagle line is that the ports are bigger and they BOTH flow 30 cfm LESS than the vortecs at 170cc. You're right, they're a much beefier head, but I still think the vortecs are a better performance choice for me since they offer adequate flow at this power level without the extra port work required.
The performer is a copy off the stock GM intake, if you are going to spend the cash buy a good intake that you can use as you upgrade in the future.....or use the cast one you already have
I see your recommendation based on that info, but we'll just have to agree to disagree. If you put a stock chevy intake (any of them) beside an edelbrock performer, you'll see that they are vastly different. They flow much better with softer turn radii and keep fuel atomized much better. But I understand why you recommend the RPM, I just don't agree with your assesment of performer intakes. I have no problem switching intakes, I just don't see the need for a 6500-rpm-capable intake for this build which is only ever going to see 5000.

SmokinLowriderSS

10-07-2006, 11:12 AM

Don't take that 6500 RPM "limit" of the Performer RPM as a "gospel" of where it works well at. If I was wanting to turn 6,000+, I'd want an open plenum single plane, As good as I think the performer is, it's NOT going to flow really freely and great right up to 6,500 RPM, and then just immediately choke off like a restrictor. It's a rahter "generous" estimation IMO, and is more valuable as a "relative" guide, than an absolute number.
The plain performer is a pretty close copy to any other dual-plane, refined better I am sure than factory iron, and has a "reccomended" RPM range of idle to 5,000 RPM. In reality, though it's going to be better than actual factory cross-H iron, it's going to work best from idle to about 4000, and start getting progressively more restrictive above that. This was really originally designed for street use and how many street cars spin 5,00 RPM for a lot of minuites and miles at a time? Very few.
The "RPM" version is very similar, sits slightly taller, and has a notch cut in the plenum divider which lets both dides of the H breathe better at higher RPM by starting to share the carb & mixture plenum directly below the carb. As such, it's going to start getting progressively more restrictive arround 5,000 RPM or so. I think the RPM version, and the Air Gap addition, are the best STYLE for most boat usage, most N/A prop boat usage anyhow. Your intended useage sits right in the heart of the design parameters of the manifold, not at it's limits.
The AIR GAP version is slightly better yet by having the whole "H" assy raised (as well as isolated from valley pan heat) which gives the ability to smooth out turns even more and keep a downward angle on the flow, less "bending", albeit only slightly, but every bit helps. My big block Performer RPM Air Gap sits the carb almost 2.5" higher on the same engine
Here is a comparison done, with an SBC, between stock iron Dual Plane, an orrigianl (old school) Performer, a Performer RPM Air Gap, and a Holley Strip Dominator manifold. Included are flow bench tests, and dyno pulls on a 383. As you are going to expect, the Strip Dom makes the most power, but that's not the point here. The point for this discussion is comparison, flow comparison, and WHERE what power is made.
Minor work like port matching is a no-brainer, should be done, by someone, it isn't hard.
http://www.popularhotrodding.com/enginemasters/articles/hardcore/0406sc_airgap/
These 2 lines were important I think.............. Fron the Dyno-pull section:
Every street guy wants the most power possible, so the Performer RPM Air Gap was pitted against the best in the Vizard arsenal: a Keith Wilson-modified Victor Jr. This, in ten years, has never been beaten for max output.
As shown, the Air Gap Performer out-performed the Keith Wilson-modified Victor Jr. all the way up to 4,750 rpm.
I drive a jet, and things are different, (somewhat). Your prop drive leans on the engine at a moderately low RPM when you are trying to accelerate onto plane, making 3,000 RPM torque very important IMO. My jet drive the moment you mash the loud pedal to the carpeting, the engine winds the drive fully to the point where drive pressureization creates so much resistance to further increase than the engine stops winding up, and holds a stable rpm. This effect is only slightly altered by boat speed, actually increasing engine RPM a bit at lower, near idle speeds from partial cavitation and reducing RPM at full speed by solid, clean inlet flow pressurization. A lot of jets run very well with single plane manifolds due to thius ability to "give up" lower RPM torque in an RPM regime it is unneeded/unused. All other things identical, a prop would seldom get away with the same engine intake/head build combination.
You are basically looking to maximize your muscle from 3,000 to 5500 RPM (give it a tad of head room, but don't get rediculous), without wasting a ton of dough or getting something you don't want. By this note, I do not think you need (or have any use for) really high-flowing heads or intake manifold, but you DO need a setup that is not excessively restrictive, something "in the middle". For what you are doing, I think any head with the flow characteristics of the vortechs (and they would likely benefit from larger valves, but maybe not the biggest) would be a good choice. Make your own decision about "brand A/B/C long-life reliability". IMO, you are pushing the 350, but not pushing it ALL THAT HARD.
Personally, I like "un-assembled" heads, as I prefer to put my own valves in them (I'm fond of the undercut Manley Pro Flow line for a few more "free" CFM), I prefer to get valve springs with my cam, from the cam maker, seems to be the best match possible most of the time.

mtnrat

10-07-2006, 11:14 AM

Curtis73 it looks like our goals are very similar. What you are finding is the same as what I am finding. I too have a good 350 shortblock and I will add vortec heads and do a roller retrofit. I have a little spare dough right now so will go the roller route, but I do not want to redo a perfectly good bottom end.

SmokinLowriderSS

10-07-2006, 11:26 AM

I stumbled across this gem, but have no way of verification (like the actual dyno pull):
On a dyno test of a Vortec 355" motor a Performer and RPM were tested. The Torque curves came together at 4600-4900. The Performer had the advantage under that, RPM over.

curtis73

10-07-2006, 11:36 AM

Ah, excellent. I see the logic now. Thanks for the clear explaination.
mtnrat: you say "perfectly good bottom end" and I turn around looking for a hot girl :)

SmokinLowriderSS

10-07-2006, 11:42 AM

I also just found this little piece of wisdom.....
Don't forget the cardinal rule of "MATCHING COMPONENTS" If the cam is designed for 5500rpm then the intake should support just over this and don't put too big a set of heads designed for more rpm.

mtnrat

10-08-2006, 07:55 AM

Don't forget the cardinal rule of "MATCHING COMPONENTS" If the cam is designed for 5500rpm then the intake should support just over this and don't put too big a set of heads designed for more rpm.
For this reason I like some of the hydraulic retrofit kits from comp cams. You get matcing cam, lifters, valve springs etc. in one package. The only downside is I cannot find bare OEM cast vortec heads. Anyone know where they may be available?

curtis73

10-08-2006, 09:39 AM

www.sdpc2000.com. Scoggin Dickey Performance. They don't list them on the website, but everyone says they carry them.
You can also get them from a GMPP parts counter. About the same price from either supplier. I think (don't quote me) they're $300 a pair naked or thereabouts. www.gmgoodwrench.com/GMPerformanceParts/Parts/catalog.jsp

mtnrat

10-08-2006, 11:47 AM

This looks interesting as the heads can handle more than .450 lift. I would need to know the spring rates to see if they match the cam I choose.
Upgraded Vortec Head Kit, Edelbrock Performer Intake
Image of Upgraded-Vortec-Head-Kit-Edelbrock-Performer-Intake-SD8060AKIT
Logo image for Scoggin Dickey Parts Center
Price: $999.95
Part # SD8060AKIT
Oversize charge will apply
Brand: Scoggin Dickey Parts Center
QTY:
SDPC Recommended Add-Ons
Description
Our Vortec cylinder head kit provides you with everything you need to install the new Vortec heads on your vehicle. The following kit includes assembled Vortec heads, head gaskets, GM head bolts, GM stamped steel rocker arms, intake manifold, intake gaskets, 12 point intake bolts and additional required components as stated.
This kit features our upgraded Vortec heads which have been modified to accept our high performance Z28 valve springs with lightweight LT4 retainers. This produces a high reving cylinder head that can handle up to 0.525" lift hydraulic camshafts. An Edelbrock Vortec Performer intake manifold is matched with this kit for optimum performance.

cfm

10-09-2006, 12:38 PM

a 300hp engine in such a small boat is not going to present a durability issue to an alpha drive - no matter what you use to build this engine.
Any heads will support this 300hp goal, as long as they are not the GM TBI truck heads.
Depending on the heads/cam used + compression you should make this 300hp anywahere between 4800-5200rpm.
A regular Performer intake is totally fine to 300hp. However, I still like the Air Gap RPM's on most 4000+rpm 270+hp engines.
The OEM Mercruiser exhaust for SBC's is totally fine at the 300hp level.
In case anybody is comparing GMPP's 290hp crate engine to this build - remember, they used a crappy cast iron quadrajet intake for this test. With a good intake these will make much more. Approx 315-320hp.
If your dead set on the Vortecs, why don't you just copy the 330hp crate engine ? 9.1:1 compression, 212, 218 at .050" flat tappet on a 112LSA and decent intake. 330hp engine.
Anyway - this is a super basic build. My recommendation is to keep it that way - SIMPLE.

curtis73

10-09-2006, 02:10 PM

That's good to know. Durability is one of my main concerns. I boat in the middle of nowhere so the nearest place I can get parts is about 160 miles away. When you get a nice vacation like that, you don't want to spend a week of it fixing stuff.
I was so worried about getting 300 but no more for that reason, but its good to hear that if I'm a little over I won't kill anything.

Aluminum Squirt

10-09-2006, 02:27 PM

I'm going to try not to get too technical here for fear of making myself look like a jackass. I was told the Vortec heads aren't bad at all. Now I'm sure there many high performance race heads that flow better, but my comparisons are whatever comes stock on a ZZ4 (355HP). I'm limited to a ZZ4 due to the class I race in. Per a knowledgable racer, the Vortec heads will make 20-30 more HP on a ZZ4 than the stock ZZ4 heads (I'm talking stock Vortec's here, no porting, we are not allowed to port, port match etc). Anyway, like I said I don't want to come on here and quote part numbers and head types, I'm not that smart an engine guy, just wanted to relate some info given to me by what I would call a knowledgable, seasoned whitewater racer. Forgot one thing, the Vortec were said to be worth 20-30 HP but also cost about 50 lbs of weight as the stock ZZ4 heads are aluminum. Also the older (or some at least???) Vortec's nee to have the top of the valve guides machined a little lower and good springs put in if your lift is goig to be above about .475. I would also recommend some good screw in studs as the press-in ones have a way of coming out at the least oportune time.
Anyway, Sorry about the rambling. Not sure if you have decided on heads, just adding a little info I've picked up in case you end up going to the Vortec's-Aluminum Squirt

curtis73

10-09-2006, 08:53 PM

I know nothing compares to actual dyno time, so that's good to see.
A head's capability is based on a couple things as far as power output is concerned; intake port volume and peak flow. Smaller intake ports create higher velocity which is good. One way to increase flow is to increase port size which drops its velocity. So, theoretically, the best ports are the ones that flow enough volume in CFM for your power with the smallest ports.
The thing that makes the vortecs kick soooo much butt is the fact that they have a 170cc intake (which is small even by performance street standards) and they flow 239 cfm @ 28" h2o. Compare that to previous GM performance heads, and the closest you'll come (of the production heads) is 211 cfm. LT-1 heads from 1971 only flow about 189 cfm at the same basic port volume.
The Vortecs (like them or not) provide AMAZING flow per cc and beat even the best offerings from Dart and a few other aftermarket companies. So, while 239 cfm isn't anything special in the grand scheme of things, at the 300-400 hp level they provide a KILLER combo of peak flow and small port velocity as-cast. Sure, they're nothing exciting to the 600-hp crowd, but for a mild build like I'm doing they are spot on
Combine that with the fact that they are $400-500 a PAIR brand NEW and ASSEMBLED, and its a combo that can't be beat.

cfm

10-10-2006, 10:14 AM

Curtis - I just looked at that DD graph you posted first.
Everything on your build looks fine - just don't go with more compression than the 9:1 you stated. Here me out for a second why - that camshaft. That cam will create a bunch of cylinder pressure. More than most any other 'shelf' cams with same at .050" and LSA #'s.
With that cam, those heads, and etc, etc I'm actually going to go against DD and say your peak hp is going to be closer to 4600-4700 . In your boat you'll probably experience some decent power drop off after this. A real dyno may not show this either, but in boat probably will.

curtis73

10-10-2006, 10:59 AM

mtnrat, go to www.vandevere.com. They're a buick/pontiac dealer in Akron, OH. They list the vortec PN 8060, assembled head at $294 each. That's at least under $600 for the assembled pair. Screamin deal if you ask me.
I'm really pissed off right now. I responded to an ad on Craigslist for new Vortec heads on a crate 350 with upgraded 2.02" intake and 1.86" exhaust. Supposedly the guy decided on aluminum. I got there and when I pulled the valve covers they were #187s... 305 castings with 1.8 intake and 1.5 exhaust. This guy still insisted on calling them vortecs.
Translation: they spent crazy money modifying #187 heads only to find out that they suck so they want to find some sucker to pass on the mistake.
I know SDPC used to sell a pair of assembled heads for $438. It was all the rage in about 2005. Car Craft, Hot Rod, PHR, all the magazines were all over it. You could even get them modified for higher lift from SDPC for $6xx a pair. I guess they caught up with the trends and they're charging more now.