Yeah Steve it was good info for sure. The heads i have are 64cc and are supposed to yield 9.19:1 comp. According to RHS they can be shaved .052 inches which should raise comp to 10.8:1. Of course my cam will change that a bit but I talked thouroughly with Jerry Cantrell from Schneider cams about my combo b4 deciding on the best cam. Its plenty large for the street, but with the gears and 4 speed it'll workCasey , I like the comparison of the 9:1 and 10:1 with different cams, and valve timing, that ndimagg posted. I remember back in the 70's I just had to have that big cam in my big block Dart and felt the loss of power. On the hi-way it had good power when I was up in the rpm's but street light to street light it was a bit of a dog.