Using state-of-the-art racing technology, Edelbrock has designed these "super cooling" aluminum water pumps to provide maximum flow, maximum pressure and equal distribution to both sides of the block within 1%. Available for most popular applications, these high-performance pumps flow in only one direction for optimum efficiency. The casting's computer-designed internal passages and CNC-machined cast iron impeller produce the maximum flow rate possible. Features include: aircraft industry clearancesheavy-duty 3/4" integral ball/roller bearings and billet steel hubs. All Edelbrock Chevrolet water pumps that may be used in race applications have a unique O-ring that provides a far superior seal than conventional gaskets. This exclusive O-ring minimizes clearance and maximizes flow for racing and heavy-duty applications. All Victor Series high-performance aluminum water pumps are extremely durable as well as efficient. Dimension from block surface to hub: 7-5/16". Fits 1969-87 big-blocks and some 1988-91 heavy duty trucks with Mark IV engines. Does not fit Corvettes or trucks over 1-ton. Includes 3/4" ball/roller bearing.Pit Stop USA offers Edelbrock Victor Aluminum Water Pump - BB Chevy - Long-Style Pump - 5/8" Pilot Shaft 8851 at low everyday prices. Be sure to check out all of our products from Edelbrock including Edelbrock Big Block Chevy Water Pumps.