S550 Rearend Swap Kit Modernizes 1961-1978 F-100 Pickups

We all tell ourselves that old trucks have character, but that is usually code for sloppy handling and a rearend that hops over every pothole. You want the style of a 1960s F-100, but you probably also want to take a corner at speed without white-knuckling the steering wheel. The problem has always been the surgery required to fix it. Usually, you have to cut up the bed or weld in complex clips. That is where the new Mustang Rear Mounting Kit from Range Industries steps in with an elegant solution.

This system changes the conversation for 1961-1978 F-100 owners. Instead of custom fabrication, you can now bolt a modern independent rear suspension directly under your classic frame. It uses the S550 or the new S650 Mustang subframe, which means you gain massive disc brakes, the Super 8.8 rearend, a limited-slip differential, and geometry designed for track days. The best part is that you do not have to sacrifice your bed space, as the kit is engineered to fit without cutting a massive hole in the floor.

Installation is surprisingly logical. The mounts make use of the original leaf spring bracket holes to locate the assembly, ensuring your alignment is true. You will need to drill some holes and notch the bottom frame flange slightly, but the Mustang Rear Mounting Kit brackets serve as their own templates to keep things straight. It comes with everything needed to mount the subframe and even includes adapters for standard 12-inch coil-overs. Just remember that you need at least 17-inch wheels to clear the brakes, and the wider track width means paying attention to your wheel offset.

This swap does more than lower the ride height. It eliminates the compromises of driving a classic. You keep the vintage sheet metal, but you ditch the agricultural ride quality that makes you hesitate to drive it on the highway.