See All 16 Photos A wide variety of limited-slip differentials have been offered for the 9-inch ... Eaton-type Positraction setup. See All 16 Photos As power levels increased, Ford realized ...

For over half a century, the Ford 9-inch rearend has been the king of aftermarket axle upgrades. Few other axles enjoy the same amount of bolt-on and custom componentry. The Ford 9-inch is a great ...

The debate within the debate has long been GM 12-bolt versus Ford 9-inch. In truth the GM 12-bolt is a far more efficient axle than the Ford because it consumes less energy. The reason for the 12 ...

The Chevy 12-bolt axle shaft (left) is tapered; the Ford 9-inch shaft is the same diameter throughout its length, except for the short section just after the spline end. This makes it easy to ...