1776p 1975-1985 Buick Chevy GM Olds Pontiac 5 9/16" short polished water pumpFlowkooler high flow pump 1776p has a polished aluminum casting with CNC machined billet impeller designed with an increased vane count and a reduced plate to impeller clearance. It achieves greater flow rates, higher head pressure and a more efficient flow. The impeller color is due to Type II Class II military grade surface coating which protects against corrosive fluids. FlowKooler introduced the first hi flow pumps and continues to improve