Chevrolet Performance oil pumps are made from high-quality materials by a name you trust. This model is designed for wet sump applications that require high-volume capacity. This genuine GM oil pump is known as a "high volume" design used on the 2007 and later LS4 5.3L W-Body applications, the LH6, LC9 5.3L Trailblazer, SSR, Truck & SUV 6.0L, and 6.2L engines with Active Fuel Management (AFM). GM engineering determined that the increased oil volume was required to meet the demands of the AFM system. This pump uses a thicker gerotor with a slightly larger OD than the 12586665 standard volume pump. Dimensionally, this pump is identical to the 12571885 high volume oil pump but is uses a different by-pass spring (42 psi). GM Engine Oil Pump Pickup Tube Gasket 12584922 not included.