Heavy-Duty Cast Aluminum Rear Differential Cover Specially engineered to minimize friction and maximize lubrication. Keep your GM rear differential running cool and clean with an upgraded cover from PPE. Precision cast from high-quality A356.0-T6 heat-treated aluminum using permanent steel molds for strength and optimum heat dissipation. Increased fluid capacity provides increased thermal stamina. This new cover is equipped with specially designed internal heat sinks and external cooling fins which increase the effective heat-dissipating surface area, helping reduce fluid temperatures. This keeps the differential fluid running cooler and provide better protection to the gears, extending differential service life. To help keep fluid cleaner, stainless steel drain and fill plugs featuring a high-power, high-temp-rated neodymium magnet are included. These magnets pull harmful ferrous particles right out of your differential fluid before they have a chance to do any damage. OEM Part Number:  22951487, 25824253, 84446288, 84553988 Note: *This part does not fit GM 9.5" (SU8) rear gear axles