All right all you techno Gods...how much material can safely be removed from the mating surface of the aluminum 4.6L 2V head? .010, .020, .030?? I need to get both of my heads resurfaced, but an equal amount removed from each. My cylinder head cc amount is 49cc's (ported PI heads) and I have 17cc dish pistons. Don't want to get any higher than 10.0:1 compression for this N/A street engine. Any problems with cam chain slop after surfacing, or will the tensioners take up the slack? Thanks.