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 ...

Without a doubt, Ford's 9-inch axle assembly has been the No. 1 choice for a performance rearend for a long time. The reasons were obvious enough—they were strong, plentiful, and affordable. A wide ...

To celebrate HOT ROD's 75th anniversary, we teamed up with CASTROL GTX to bring you some of the stories that exemplify the core of what HOT ROD is and reflect the brand's influence on America's car ...