You always want to mill combustion chamber and intake surfaces of the heads. That way you don't wind up with a "custom" intake manifold that only fits one motor. Rule for SB Mopars is you take 95% of whatever you take off of the chamber surface off of the intake surface. For example, .030 off chamber surface and .0285 off intake surface.
Thanks - yes I just found that out, what you just said, in the post that TMM sent me. Very good info, much better idea to shave the heads both surfaces than a brand new M1 intake! And the 95% rule is what I was needing also
