I originally had intended to use the stock rear setup from an 1980 model Trans Am for the project due to its rear wheel disc brake setup. However, after I mounted it up on the car, I was not happy with it. I knew I wanted to go with larger tires under the rear without it sticking out. I decided to do my own version of a mini-tub and move the leaf springs in to accomodate the larger tires. This was before there was any "kit" for the 2nd gens out there.
However, I ran into a few difficulties - first, the rear frame rails swing outward 1/2 way through the rear wheel opening, severely cutting into the space for the wheel and tire. Secondly, there was no good way to make /or adapt a bracket to move the leaf springs without binding it up at the front eye.
So I got a little radical here. I ordered a 4-link setup from Martz Chassis and a set of Competition Engineering Formed rear frame rails. I cut the factory rails completely out and used the CE ones to get rid of the factory flair out. I then attached the Martz setup to the CE frame. Since I was going that far anyways, the 8.5 10-bolt was replaced with a 9-inch too at this time.