1965-78 Chevy Big Block Aluminum High Volume Short Water Pump - Natural High volume, lightweight aluminum short water pump (SWP) for Chevy 396-402-427-454 big block engines. Features a CNC machined iron impeller, a heavy-duty shaft with 5/8" pilot, ribbed aluminum housing, and a heavy-duty ball/roller bearing assembly which flows 35% more coolant than your standard pump. Fits 1965-78 Chevy big block passenger cars, 1966-72 350 Chevy trucks, and 1969-70 big block Corvettes.