The Edelbrock Polished Victor Series Water Pumps are designed to produce maximum flow, maximum pressure, and equal distribution between both sides of the engine block, within 1percent. They are ideal in preventing overheating in street rods, street machines, muscle cars, tow rigs, and RVs. This 5/8 pilot shaft, water pump has a left hand inlet with no back plate. 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. 70 and its inlet diameter is 1. 78. These 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. Other features include heavy-duty roller bearing assemblies built to withstand higher torsional loads, billet steel hubs, and leak-proof seals.