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 narrow ...

Pitching the stock differential out from under a GM car in favor of a 9-inch Ford has always been the best way to step up the drivetrain for drag racing. Since the price of used 12-bolts has ...

Whenever you're building a hot restomod, thoughts always eventually turn to the rear axle. At one time, choices were simple: 8- and 9-inch removable carrier differentials and housings, two-pinion or ...

Sooner or later, it boils down to what direction you're going to go when your Mustang's rear axle wears out. Some decisions are straightforward. If you have a six-cylinder Mustang, stick with the ...