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 ...

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 ...

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.

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 ...

From the archives: Legendary tech guru Marlan Davis explains why the 9-inch Ford is the strongest rearend out there—it’s all due to “hypoid distance.” To celebrate HOT ROD's 75th anniversary, we ...