My 74 with stock heads has been reported to have either 7.5:1 or 8.0:1 compression. If I replace the "stock" (meaning these are what I put on last time I took off the heads) FelPro gasket with steel shim gasket, how much compression increase would I see, and how much Horsepower? I saw a chart on someone's website where the old 302 had 9:1 with 210 HP. THen they dropped to 8.5:1 -140HP, then 8:1 with 138 HP. I don't see a curve in these numbers that lets me estimate what I would have with 9.5 or 10:1 (not that I could get these higher numbers with a gasket replacement. Anyone have real numbers?