Upgrading your Mustang's drivetrain will not necessarily add horsepower, but these mods will help you get down the track and road much quicker. StangMods carries a large selection of Mustang Gears, Traction-Lok Differentials, Mustang Short Shifters and Clutch Components. StangMods offers the largest selection of Ford Racing & Motive gears for the 7.5" V6 rear end and 8.8" V8 rear end.