1967 Plymouth B-Body Rear Suspenison -The (Found) Link - Tech

The idea for changing the rear suspension on a muscle Mopar came to mind while walking the Manufacturers' Midway at the '07 Mopar Nationals. There we noticed a triangulated four-link rear suspension system-originally designed to fit an A-Body Mopar-at RMS Suspension's booth that really caught our eye. After talking to RMS Suspension's Bill Reilly about the system, we decided we needed to take a closer look at this cool setup.

We came back from the Mopar Nationals very excited about the idea of doing something cool and different. We were also curious to see how well the A-Body system would fit.

The problem we did encounter at the time of planning was that there was no system offered for the B-Body we planned to work on. In our discussion with Bill, he agreed to send us an entire A-Body system to see if we could make it work in our '67 B-Body-with minimal altering of the components.

After Bill sent the A-Body kit, we dug into it to see if it would actually work on our '67 B-Body in its unaltered form. Surprise, no go. We contacted Bill and showed him pictures of how it wasn't going to work. At this point, he thanked us and told us to keep the hardware for our time and effort put forth.

Now, since we had some hardware to play with, we were destined to design our own triangulated system for this B-Body. We started off by finding exactly where we wanted the rear axle to be located in the car. We chose a location that set the rear axle back about 3/4 inch and slightly higher in order to lower the car. We did this to make room for taller tires and to give the car a more aggressive stance. Now with the rear axle in the desired ride height position, we used the adjustable lower bars from Bill's kit and made adjustable brackets that attached the lower link bar to the body of the car where the original leaf-spring hangers would have mounted.

The next step was to create a structure that would attach to the framerails. We wanted this structure to be strong, and we also wanted to be able to mount everything to it except the lower four-link bars, which would mount to the chassis and to the axle. So with the help of coworker, Ron Linton, we came up with the required brackets and mounting points needed.

We started by cutting out the car's original crossmember. With that gone and everything ground smooth, we now had the desired space needed to make the structure. We wanted the structure to have secure mounting locations where it would attach to the framerails of the car. There are actually two crossmembers in this structure: a front and a rear. These two crossmembers are connected by two chrome-moly bars that are welded between them. This new boxed structure with two crossmembers is what gives us the four mounting points. This is necessary for high-horsepower applications. Since the upper link bars attach to the chassis of the car at the structure, a great torsional twist is applied to it due to the force from pinion rise during launch and under acceleration through those upper four-link bars. Because of this torsional force, it was necessary to spread that energy over a greater area of the chassis-the reason for the four mounting points.