Hate to do it

The Jeep Grand Cherokee 8.25 with disc brakes is $225 bucks at the U pick it here.
About 4 inches too wide for the Swinger, but can be made to work with rim offset.
You would however still need to have all the Cherokee mounting and suspension garbage cut off and the A body perches welded on and the driveline shortened.
Taking into account I can do all the above myself it would only cost me a few hundred total, but if you or a buddy can't do it the labor is going to push you somewhat (3-4X) over the original cost of the rear end.
There is a good amount of aftermarket parts and support for that rear end also since craploads of Jeeps run them.