1734 1970-1984 Inline 6 cylinder 151 250 305 CW Rotation 3 11/16" water pumpIf your running a riser set up and find your heat cycling it might mean trapped air. The best solution is to build pressure to and the best tool is pump 1734. We designed a impeller with an increased vane count and a reduced impeller vane clearance to take build that pressure. 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