[DAVID GAGNARD]

Compression ratio and cranking compression are two different animals.........

The cranking compression has a lot to do with the camshaft profile, probably more so than anyhting else...(assuming a good ring seal and good valve seal) the amount of overlap in the profile has a ton to do with cranking compression....

My 10.5 to 1, 351-W cranks out at about 125 psi, but my camshaft has a lot of overlap and at those low cranking speeds, bleeds off the compression as it is designed to do. by contrast, I checked a bone stock 351-W and it's cranking compression was 145 psi!!!!!!!!!!!

doing a cranking compression test is a good way to check for ring sealing and valve seat wear/sealing, not a good way to determine overall compression ratio...

David