Pontiac specific water pump pulley alignment shim kit. Finally now available kit to include 5 correct shims .040 each made just for the 1955 and newer Pontiac V8 engines. This precision set is made to align the pulleys which are never correct. Now you can dial in your pulleys to perfect alignment. 4 bolt holes with center .626 shaft center hole diameter. Fits all Pontiac pumps to include Super Duty 421, 455 and Ram Air cars. Tired of Chinese made " Universal fit junk"... we are....