1969-87 Chevy Big Block Aluminum High Volume Long Water Pump - Natural High volume, lightweight aluminum long water pump (LWP) 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 1969-87 Chevy big block engines and some heavy-duty trucks with Mark IV engines.