That explains it. I have a feeling the guy who sold it to me in the 80's had used lots of random spare parts he had lying around. I bought it from a high ranking local racer. It also has a wide Cat front bumper, a Cougar rear shock/wing mount, and a Cougar wing.
My home made alu housings worked perfectly and center the diff in the with no pre-load. If I paint them black, noone will know the difference.
My diff plate carriers are made from aluminium. You can imagine my confusion when I took the diff apart to service it as a kid, and saw that the manual said to glue sandpaper to the washers. "What's the point?" I thought to myself.