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Originally Posted by lust4speed

Don't have the heads cut until you actually measure them. 100 is a nice round number and I would want to insure that is what the chambers measure. Also, measure both heads since they might have received different clean up cuts in the past. The Rhoads lifters will increase your effective compression ratio since it will mimic a smaller cam at idle. Just my 2 cents, but I'd be shooting for a true 9.3:1 ratio.

edit: According to the Wallace website calculator, a change in compression ratio from 9.3 to 9.5 on a 450 horsepower engine will result in a whopping 2.6 horsepower increase.

Guy who I'm buying the heads from measured them at 100 ccs, but I'll double check when I get them home.

IIRC, a full point compression increase results in about 4% hp increase, so increasing a half a point (9:1 or so to 9.5:1) should get me 2% increase, or about 10 hp on a 500 hp engine.

Thanks

Scott