1969-76 Chevy Small Block Aluminum High Volume Long Water Pump - Chrome High volume, lightweight chrome aluminum long water pump (LWP) for 1969-76 Chevy 262-305-307-327-350-400 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.