1955-78 Chevy Small Block Aluminum High Volume Short Water Pump - Chrome High volume, lightweight chrome aluminum short water pump (SWP) for Chevy 265-283-302-307-327-350 small 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 1955-78 Chevy small block passenger cars, 1969-70 350 Corvettes, and 1955-72 light-duty trucks.