I really didn't feel like going into it that far. I just want to mill the heads to bump the compression up a bit. Looking in the old Mopar Engine book it says .090" of clearance is safe for an auto trans. Based on that I could take .030" off and pick up a half a point in compression. Like I said...all I need is another tenth or two in ET to have a solid 11.5 which is my limit because the car isn't caged.