Customer:"Hello? I'd like to buy an axleshaft for my Ford 9-inch rear axle." Salesperson:"No problem. Do you know what length, spline count, and wheel-bolt pattern you need?" Customer:"I really don't.

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 ...

There are many reasons to run a high-pinion differential in a 4WD vehicle, and there are many reasons to run a Ford 9-inch axle. When used in the front of a vehicle, high-pinion differentials ...