I have a stock lq4 and some ls3 heads. I am wanting to get ~10.5 compression from it. How much would I need to shave off and what head gasket to achieve this? It will be flycut so that's not an issue. Thanks

 

If you run a .040" gasket and mill the heads ~.045", giving you a 64cc chamber, you should be able to get up to 10.5:1.

 

Knocking .045 off will only knock it down to 64cc? I have searched a lot on here and seen some people say .040 off will be 61-62cc , .030 off will be 5-6cc off etc. Is there a definite answer to how much off equals 1cc? Is it safe to go .045 off? Lots of different opinions on that too. Kinda don't know what to believe at this point.

 

We usually measure .006-.007" per cc in chamber size, so if you mill .040" off the heads you will be right in the correct area for chamber size. Sorry I had a brain fade on the first number.