Dave,make sure you do a good job of getting rid of edges & angles on your pistons. I used a Dremel with a light grit stone to get rid of any edges on valve reliefs & put a very slight radius on edges of pistons. Followed this up with a good polish with 1200 grit sandpaper. If I were you, I would also consider going to a flat top instead of cutting those heads. In my experience I have always seemed to get very good performance out of lower compression race combos using flat tops. I know money is an issue here, but in the long run those heads are very expensive & I think you will be limiting your future options. Good luck with whatever you decide, let us know what the end result is. Randy