The Edelbrock Polished Victor Series Water Pump provides maximum cooling for the street and the racetrack. They are ideal in preventing overheating in street rods and street machines, as well as in tow rigs and motor homes. It includes aircraft industry clearances, heavy-duty 3/4 ball/roller bearings, and billet steel hubs. The dimension from block surface to hub is 5-3/4 and its inlet diameter is 1. 78. The aluminum pumps have CNC-machined housings with special one-way internal passages that flow more coolant at higher velocities, even at low engine speeds. The CNC-machined, cast iron impellers are larger than other impellers. They have curved vanes that produce greater flow with less cavitation.