Need some advice please. 468 BBC

[1975 WRIEDT MAVRICK]

I bought a bought as most of you know with a 468 BBC in it. I have a friend that looked over the externals of the motor and said you have a good start. Edlebrock intake, erson roller rockers, cam? mild im guessing, and 8 to 8.5.1 pistons. The heads are the 781 heads, valve size I do not know yet. I have asked a few people about these heads and their performance and got way more answers than I can compute in my head and figure out was is real and what is sureal. If anyone can enlighten me I would appreciate it. I would like to rebuild the engine for mainly two purposes. 1...Reliabilty2...Mild performane. What is my best combination with what I have to work with here. 1 Friend says the heads are boat anchors, and 1 says they are the second best heads I CAN BUY. I AM MORE CONFUSED THAN A THIRD GRADER IN CHINESE ARITHMATIC.......PLEASE HELP ME. I would like to see 5500 to 6000 rpms. And I do not know yet what impeller I have but it is an American Turbine pump.
Thanks in advance..... :cry:

[sleekvino]

I bought a bought as most of you know with a 468 BBC in it. I have a friend that looked over the externals of the motor and said you have a good start. Edlebrock intake, erson roller rockers, cam? mild im guessing, and 8 to 8.5.1 pistons. The heads are the 781 heads, valve size I do not know yet. I have asked a few people about these heads and their performance and got way more answers than I can compute in my head and figure out was is real and what is sureal. If anyone can enlighten me I would appreciate it. I would like to rebuild the engine for mainly two purposes. 1...Reliabilty2...Mild performane. What is my best combination with what I have to work with here. 1 Friend says the heads are boat anchors, and 1 says they are the second best heads I CAN BUY. I AM MORE CONFUSED THAN A THIRD GRADER IN CHINESE ARITHMATIC.......PLEASE HELP ME. I would like to see 5500 to 6000 rpms. And I do not know yet what impeller I have but it is an American Turbine pump.
Thanks in advance..... :cry:
well frist off to spin those type of rpms you need some big horse power,your head are as follows ,336781 made from73-85 oval port open chamber 118cc chamber 256/116cc ports thats your specs for your heads, .to make that kind of rpms you could cut your impeller to a b cut but then you loose hole shot unless you have a beast that has some good power say around 550 700 hpfor that you better have some dough.if you want to have a fun motor go for some good stuff like forged pistons,nice cam,run around 9-9.5to 1 you will enjoy it more just try and shoot for 475-500 hp and see what happens and if all else fails throw some juice through it,a nice 100hp shot in it will get things going.

[SmokinLowriderSS]

Negative sleek, the '781 heads (and their replacement the 353049's) are the "large oval" port heads. They are the hot ticket for middle-RPM power in a 400"-500" engine, mid-RPM being 5,000 to 6,000 RPM. The small ovals (peanuts) are aprox 200 CC intake ports. The larges STILL bennefit from a mild porting job and the larger valves in a boat aplication. I think this would be a better direction than rectangle port heads as the muscle in the 4k to 5k range is still important in a jet. I've seen engines over-optimized for high-RPM, that couldn't spin the pump that fast.
Stick with 5500 RPM for starters.
Let's assume you have an "A" impeller, you'll need aprox 530 HP @5500 RPM. That's not that hard to get, AND be reliable. There's lots of threads on build advice arround here.
Have the heads ported, new, heavy duty undercut valves (for best flow), build 10:1 CR, ARP rod bolts, ARP stud the bottom end, good windage tray, oversized oil pan (and likely a cooler too depending on how long you plan to run hard at a blast), a single plane manifold (or at least the Ed. Performer RPM manifold, Air Gap a plus), headers (get the vaseline out, this'll hurt), Cam arround .600" lift, stay UNDER 290* duration seat-seat IMO. That's kind of a ballpark, and is also where my 454 is headed as budget permits.
I'm making 400HP on 8.5:1, the above Air Gap manifold, 1ea 700 CFM Holley, .565" lift 280* dur Isky stick (Hyd), stock '049 heads, Lightning thru-transom headers, 5,000 RPM. Nothing fancy, but she's solid, and capable of much more with improved breathing, easy.

[Jetmugg]

Keep the heads, get a new friend, one who knows something about BBC heads. The 781's are some of the best flowing large oval port, open chamber heads. Plus, they are fairly plentiful. They won't hold you back, but I suggest reducing your RPM range a bit, try to keep it under 5500.
My 2 cents,
SteveM.

[SmokinLowriderSS]

Keep the heads, get a new friend, one who knows something about BBC heads. The 781's are some of the best flowing large oval port, open chamber heads. Plus, they are fairly plentiful. They won't hold you back, but I suggest reducing your RPM range a bit, try to keep it under 5500.
My 2 cents,
SteveM.
Yea, what jetmugg said. :)

[cstraub]

I bought a bought as most of you know with a 468 BBC in it. I have a friend that looked over the externals of the motor and said you have a good start. Edlebrock intake, erson roller rockers, cam? mild im guessing, and 8 to 8.5.1 pistons. The heads are the 781 heads, valve size I do not know yet. I have asked a few people about these heads and their performance and got way more answers than I can compute in my head and figure out was is real and what is sureal. If anyone can enlighten me I would appreciate it. I would like to rebuild the engine for mainly two purposes. 1...Reliabilty2...Mild performane. What is my best combination with what I have to work with here. 1 Friend says the heads are boat anchors, and 1 says they are the second best heads I CAN BUY. I AM MORE CONFUSED THAN A THIRD GRADER IN CHINESE ARITHMATIC.......PLEASE HELP ME. I would like to see 5500 to 6000 rpms. And I do not know yet what impeller I have but it is an American Turbine pump.
Thanks in advance..... :cry:
First we need a budget.
Second we need your goals for the engine
Third The board will "discuss if one and two can add up to four.
Four The engine is built and we see if we accomplish the goals within budget.
So, how much do you want to spend?

[396_WAYS_TO_SPIT]

First we need a budget.
Second we your goals for the engine
Third The board will "discuss if one and two can add up to four.
Four buil engine and accomplish goals within budget.
So, how much do you want to spend?
I would really listen to this guy!!!!! He lknows his schit;)