Performance info for 170 CI

You cannot guess, assume, or use somebody else's numbers. There is way too much variation, not just across different heads and blocks but even in different combustion chambers in the same head. You must measure your cylinder head and your piston deck height to determine your starting combustion chamber volume. That's the only way to figure out how much to remove from the head (and/or the block) to arrive at the compression ratio you want.

Otherwise you are pissing (and barfing) into the wind.