hello, i just need some help with some compression ratio things here. i just picked up a very cheap set of "336x" heads and i am right now port matching and just cleaning up casting slag and smoothing them. im not going crazy on them i just want them to match and be a bit better flowing. now to my qusetion. they are 76 cc heads and i was going to polish the combustion chambers, just to make them smooth and no places to cause pre-detenation. i can not find out what my compress ratio will be. i do not know what cc'c will be gone out of the head's by knocking down the rough casting. just wonder if somebody could give me some input on that. specs below.

- 350 v8
- 4.001 bore and 3.48 stroke
- 76 cc heads (maybe 78 after polishing?)
- +5 cc dome pistons 4 valve reliefs
- no machine work

what size shim head gasket will be needed and i do not know how far the piston is down in the bore but i am guessing it is stock. i want as high compression ratio as i can get (wont be that high i dont think deffently under 10-1) with out machine work. maybe even if somebody could give me a formula i could do it on my own.

 

About 9:1 if you're lucky.

 

What size head gasket would that be with?