compression ratio?

[Terrible Buddhist]

can anyone guess how much these heads are going to raise my compression ratio? Are these going to be good heads for a big cube big boost engine I hope to build someday?
GM Bowtie rectangular port heads # 14044861. These heads have 380 CC runners. They are 106 CC open chambers. They have been angle milled .125. The valve sizes are 2.25 / 1.88

[Snowboat]

I have a pair of those heads also, but mine have been worked over and the cc is 114. I believe the book says they are supposed to be 112. Either way, I would cc them before figuring the CR. Also, Fiat told me to get some Ford head bolt washers, or another hardened washer, to keep them from pulling through. Arp washers tried to pull through and there is a slight indentation in mine. I have enough stud to double washer. When I reread your post I see that they have been angle milled, maybe you have already cc'd them.

[Fiat48]

The GM performance book shows the head has 115 cc chambers, but the quick reference chart shows it has 105 cc chambers. I'm willing to bet the head has 115 cc chambers and the 105 is a misprint. However, since you are angle milled .125, you could indeed have 105 cc chambers now. As I remember, .125 angle mill takes about 10cc out of the head. The head is the W port configuration, but I see that's been changed by the head porter.
Compression ratio will really depend on what you are working with but here's an idea of the 10cc differnce:
468 cubic inches, 115 cc chamber, 0 deck, .040 gasket with 4.310 gasket bore size, 0 dome volume = 8.68 to 1 compression ratio.
105 cc chamber = 9.35 to 1. An increase of .67 in compression ratio.
This compression increase for small chamber will increase as the cubic inch goes up. Figuring a 509" motor shows a .72 increase in compression.

[Terrible Buddhist]

wow...thats some great info! Eventually I want to go up to about a 550...do you think these heads will be good for that...and do you think they will work well now?

[Fiat48]

The heads will work fine but do have a couple issues. Use a large OD head bolt washer (Ford). Also these heads have small seats in them, rather fragile. Keep valve spring pressure up if roller cam to keep from pounding these little seats. For alcohol use, have bigger seats installed.

[Terrible Buddhist]

Right now I am running a hydraulic cam and under 10 lbs of boost on a 468...eventually I am hoping for around 22lbs and 580 cubes...all in time

[Badboat1]

That head is out of the box 114 to 115 cc and do the math approx. .006 per cc milled off would be 95cc chambers at a .125 flat mill.We have had them down to 70cc's and not hard to do.So I would make sure I had one chamber cc for sure.
Badboat1

[Terrible Buddhist]

did you run these heads forced induction?

[Badboat1]

To run a head that small would not be a shelf piston and on a reliable engine blown or forced induction 8.5 is max with some boost the turbo stuff I do 7.0 and make 2200hp but race gas. CC it first and will figure options to make it work for you I have the same heads on my lake boat and they are 110cc.Mine were raw castings and they do have the big seats in them that.Mine did not have a bolt hole or guide holes at all.It is a old pro stock head and the guy that designed it for GM was Phil Coleman that was at Reher-Morrison.
BB1