Why didn't you just cut the pistons in the area in question? I'd sure be complaining to someone about having to cut/grind on either one for what one of those kits cost. I understand if you had to cut on the engine block for a little clearance for the 4" stroke but the piston/crank clearance should have been correct as purchased since they were designed to work with each other. You are using their rods, too, correct? That stuff is supposed to be a matched setup that just drops in is what I have read.