There found in late year B body cars and trucks. There an option to cut down for any car, though it is an expensive issue where you might be better off getting and building up a 8-3/4 or purchaseing a DANA outright.
There plenty strong with a decent gear ratio selection from 3.21's up and beyond 4.56's if you turn the right stone to find it.
If your building a Cordoba, Magnum, etc... there a cheap rear to get and willl take to the car with ease. Often, there spring mounting pads are different then what you normally see due to the then new "ISO" mounting system. If you don't know what they look like, there like a '79-ish Camaro. Leaf spring sandwiched between rubber buscuits.
Not a performance oreiented (SP!) idea, but the do ride a little smoother. They can be deleated with use of the old material retro fitted on. Below is a picture of one with old age. "B" body U brackets are not available, but other body styles are. I found out the hard way they do not swap.
The next picture shows the rubber biscuits better.
Then some old age damge shots.
From these shots, you can see what needs to be done to swap over the old mount system. This is not easy work and rookied should not attempt this, not without help that's for sure.
