I'm not sure if this was directed at me, but I think 73 CC's was what I got, and I only did 1 on each head to get a vague idea of my compression level. The nail head valves take away CC's, and they had a light mill to flatten the decks. You could get well over 10.0 to 1 with a thin steel head gasket, but you would have even less room for a cam. I hope to swap to the old MP .528 solid, which I have been informed fits, but not much more.