Brake Upgrade Idea

[insite]

okay, looking at the specs for the base 986 vs. 986S brakes, i notice that the pistons are identically sized.

i know the pads are a few millimeters taller and wider, but what's to stop us from shimming the calipers away from the steering knuckle and mounting 986S rotors? can anyone who has the parts handy check to see if 986S pads will sit properly in a 986 base caliper? what, if anything, keeps them from sliding in? thanks.