340 improvements with dyno numbers

Most of them I checked were in the 9.00 to 9.50 range but it's not the head volume that was the issue. With a shim gasket, the piston has to be out of the bore at least .017-.018 and most are .010-.015 down the bore.

My current build is 11.08:1 actually measured with a small dome and out of the bore .045 IIRC I'd have to pull the but it's all that and STILL only 11:1. I can get to 11.25:1 with a gasket change if I want to.


Most guys who don't downfill the bore and do the math don't have near the compression they think they have.