If I use the piston I have it puts me @ 10.6 cr with the 80 cc heads and a .039 gasket. I do not want to deck the block as it is a #'s match for the car which is kinda why I like the stealth heads. When you say change the cam, any one in particular and please give reason for doing so. BTW the piston is .010 in the hole now. The 84 cc edelbrock heads would put be compression and quench where it should be but vanity has the better of me so I am using the Stealths.