compression ratio

What he said. The 318 is really annoying when you want to up the comp. I have one with stock pistons @ .030 over. Used the Mr Gasket thin head gaskets, which if I recall are about half the thickness of the Felpros. Used closed chamber 273 heads which are supposed to be something like 57cc, they are not even after milling. After all of this according to my measurements I'm right in the 8.5 comp neighborhood. Would have liked at least 9, but it will be alright.