slant 6 head shave

Rocco
Actually you are close. Charrlie runs 170 CI slants so the motor is a little different that a 198/225. The 170 is a Zero deck motor unlike the others.
Limiting factor on cutting the head. HUM not quite a fair question. You need to figure on both the head AND the deck. I may cut .150 off the combination of the 2. I know people who cut it all off the head and some cut it all off the deck. I like a combination of the 2. Do you have any idea of whether your motor has ever been rebuilt? Is this hypothetical or do you need real numbers? The Actual number is .0067 = 1cc. Other factors are what head gasket will you use, what bore size, etc.
Might be better to PM me if you need build help.
Frank