Ford stopped making the 9-inch rear end in 1986, but aftermarket companies are still making parts for the axle, and racers still rip down tracks with it.

Detailing a rear axle is a major part of a Mustang concours restoration, right up there with the engine and the front suspension in complexity. There are so many parts, colors, codes, machined ...

So if simple math wasn't your thing in school, then narrowing a Ford 9-inch at home might not be the job for you. But if you're the type of hot rodder who likes a challenge, then this old-school ...