It depends what you want to be at with your C/R, but likely you wont be able to raise it enough with those heads if you're using flat tops. Im building a 505, and using flat tops....with a 0 deck block and 100 cc chambers, I'll be at 10.2/1.... Your chambers are likely around 118/122 cc's, milling the heads 6 or 7 thousanths gains about 1cc. See what I mean? Go for a small chamber head is you want to leave the same pistons. 215's maybe or 290's. As far as cutting the intake, I once had a set of heads flat milled 45 thousanths, and the intake still fit OK....barely. It depends on the heads and intake. John