Loading... Please wait...This Main Stud Kit fits all cast iron SOHC and DOHC 4.6 and 5.4 Blocks with 2 bolt mains and without factory windage tray. Fits all Mustang GT, F150, Navigator, Lightning, and 2003-2004 Cobra engines. Main Stud kits strengthen your bottom end for a bullet proof setup. These main stud kits are designed to increase clamping load without stretching and are a must in high performance applications.