pump gas build

With a slant six, no matter what else you might or might not do, at least bring the compression to stock spec. Depending on what manual you look at, the spec is listed as either 8.2 or 8.4 to 1. I have never taken a slant apart, and got a actual measured ratio of more then 8-1.Most were in the 7's, and that was with stock pistons, and a "shim" gasket. Any aftermarket head gasket will be thicker, and I have read about some replacement pistons that are lower in the bore, so that would hurt compression even more.