I have a 1972 429 unfortunaletly came with the D2VE heads and only had an 8:5:1 compression but I switched over to D3VE heads, and it feels I have a bit more power than before, Ive read the D2VE heads had larger combustion chambers than the D3VE heads and was also open chambers, but the D3VE heads are closed chambers and look to have a smaller cc, what Im trying to figure out is my compression ratio now, I have searched for days on the net trying to get answers but none yet ,anyne know?