1) This Is An Aluminum High-Volume Long Water Pump For 1969-1987 Small Block Or 90-Degree V6 Passenger Cars, And 1973-89 Light-Duty Trucks. Fits For SBC 283, 305, 327, 350, 383, 400. 2) This High-Volume Pump Will Flow Up To 40% More Than Stock Pumps And It Will Dissipate Heat Better Than Regular OEM Iron Pumps. 3) This Water Pump Is Lighter And Features High-Quality Roller Bearings, A Custom Machined Impeller For Maximum Water Flow, And Reduced Cavitation At High RPMs. 4) Block To Hub Measurement Is 6 15/16". Large 3/4" Bearing With 5/8" Shaft. 5) Standard Rotation. 6) The Pump Will Clear Cam Belt Drives And Most Blower Drives. 7) This Is The Long-Style Water Pump, It Must Be Used With A Pulley And Brackets Made For Long Water Pumps. 8) Gaskets Included. 9) Package Includes: As Shown In.