The Edelbrock Long High Volume Victor Series Mechanical 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. This water pump has 3/4 inch ball/ball bearing. The dimension from block surface to hub is 5-3/4 and its inlet diameter is 1. 95. 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. It has curved vanes that produce greater flow with less cavitation. The CNC-machined, cast iron impellers are larger than other impellers.