1688 1984-1991 SBC Corvette short shaft 3/4" shaft water pumpFlowkooler's pump 1688 for the small block chevy Corvette engine has a 16 blade skip vane impeller that is CNC machined from billet aluminum. An increased vane count and a reduction in the plate impeller clearance achieves greater flow rates, higher head pressure and a more efficient flow than other OEM water pumps. It is then surface coated with a military grade type II Class II anodized finish. FlowKooler introduced the first hi flow pumps and