Water Pump Each pump is manufactured from T6 aluminum and features an impeller with curved vanes for maximum flow, pressure and equal distribution to both sides of the block. It also features a unique seal assembly for leak proof operation. 3/4" shaft with 5/8" fan pilot snout. 1/2" NPT hole on passenger side (for heater hose) and on top (for bypass hose) Stamped steel rear plate. Extra thick fan hub. 3/4" ultra duty bearings. Adjustable cam stop. State of the art aluminum castings. Equal flow to both cylinder banks. Precision impeller. Higher flow rate and pressure rate. Weighs 6 lbs. Does not have a set screw retaining the fan hub. NOTE: This pump is designed for street use and is not to be run on a motor which exceeds 5,500 RPM. Learn how to choose the correct water pump for your application by reading our tech article. SBC - Short vs Long Water Pump. Pulleys and Belts Speedway Cast Aluminum double groove pulleys for Small Block Chevy feature a 20% reduction. Reduction pulleys have a smaller diameter which slows the speed of your fan, water pump, and alternator to reduce drag for more top-end horsepower. Plus, high RPM water pump operation is improved due to reduced fluid cavitation. Machined from lightweight cast aluminum. Superior belt retention with extra-deep grooves. 20% reduction slows accessories down for less drag. Adds top-end horsepower. Reduces water pump impeller speed below cavitation threshold. Improved high-RPM cooling capabilities. 910-15482 6-5/8" O.D. 910-15484 5-7/16" diameter. Note: The lower crank pulleys are manufactured thicker than normal stock pulleys. This requires longer 3/8" bolts to be purchased separately. Allen head type bolts recommended. Get the correct pulleys for your application by learning which water pump you have as explained in our tech article. SBC - Short vs Long Water Pump. Kit Includes (1) Small Block Chevy Aluminum Short Side Water Pump. (1) Aluminum Allen Pipe Plug, 1/2 Inch NPT. (2) Aluminum Pipe Bushing Reducer Fittings, 1/2 NPT to 3/8 NPT. (1) Small Block Chevy Cast Alum. Short Pump Double Groove Pulley. (1) Small Block Chevy Cast Alum. Short Pump Double Groove Lower Pulley. (1) Matched Belts for Cast Aluminum Pulleys 910-15460. (1) Aluminum Lower Pulley Screw Kit, Fine Thread. (1) Aluminum Lower Pulley Spacer. (1) Universal Water Pump Shim Kit. (1) Aluminum Freeze Plugs with Return Set. (2) Black 90 Degree -8 AN Flare to 1/2 Inch NPT Pipe Adapter Fittings. (2) Black Straight -8 AN Flare to 3/8 Inch NPT Pipe Adapter Fittings. (2) Fragola 482508-BL AN Flare Tee Fittings, -8 AN to 3/8 NPT, Black. (6) Black Socketless Straight Push-On Hose Ends, -8 AN. (2) Black 90 Degree Socketless Push-On Hose Ends, -8 AN. (1) Aeroquip Special Application Socketless -8 AN Hose, Black, 6Ft Length.