Seen thread long time ago on maximun decking of open chamber heads. I am building a 413 for a friend and putting on a set of 452 heads for the hardened seats and unleaded fuel. The only pistons available without going to custom are Speed Pros with a compression ratio of 9.7 to 1, that is with stock closed chamber heads. By putting on a set of open chamber heads I believe the CR will drop to 8.5. To bump this up can we safely remove at lease .050 from the heads and use a thinner head gasket? This should move the CR to at least 9.3. Any info or ideas? Any other problems I need to look for in doing this? I'm sure others have done this already.This is going into a street driven car. Any ideas for a good camshaft to move up the cylinder pressure also? Thanks I want to do it right the first time.