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I looked over some automotive machinist refernce books and if they are correct(and at $65 a volume I will assume they are) to raise the compression on a head, a cut of 0.010 will raise the compression from between .141:1 to .200:1 depending on the the swept volume of the compression chamber so if an unmolested 194 head will raise the compression .500:1 it would take a minimum of an additional 0.075 cut to reach a 2 point increase in compression.

Automotive technology: a systems approach, Volume 2 By Jack Erjavec