I am currently have a set of JE pistons that are at the machine shop with the block for boring. I found that the top of the piston in the ring land area is much smaller than the skirt(what little there is). I measured, but cant remember the exact number. I believe there was at least .020 difference from top to bottom. I would check the clearance at the skirt. If it is .020 there you are screwed, but I am betting it will be around .003 if your machinist did his job. You will hear that forged pistons need .005-.01, but new alloys used in pistons today are much different than those of yesteryear. Todays forged piston dont require the clearance that old ones did. My sbc 400 TRW forged pistons were fit at .003 wall clearance and there is no rattle when it is cold. Hope this helps.