The XDP X-TRA Cool Water Pump (Pump Only) XD678 is a direct-fit replacement for the failed component in your GM 6.6 L5P Duramax. This water pump utilizes high-quality materials in the manufacturing process and is made to the same high-quality specifications as the factory pump. This is sold as the water pump only, no housing included.Features: High-Quality MaterialsDirect-Fit ReplacementIncludes Mounting Gasket2 Year/Unlimited MileageSpecs: Housing Material: AluminumHub Height: 1.433 InchImpeller Material: PlasticImpeller Rotation: ReverseImpeller Vane Quantity: 7Mounting Hole Quantity: 6Notes: The harmonic balancer bolt will need to be removed to replace your water pump.The factory bolt is a torque-to-yield fastener (TTY) for one time use and must be replaced.