This finned, cast aluminum cover is designed by Ford Racing for the 8.8" Ford rear end. The aluminum cover is stiffer than the stock steel cover, while the cooling fins help to keep gear lube temperatures down. Because the stock mounting hardware does not work with this cover, special mounting bolts are included. Fits live axle only, not for IRS. This is the same rear cover supplied on the 2011 Shelby GT500.