I'm not sure if rangers ever got rear disc brakes, I cut down a 97 explorer rear for my car, after the swap I measured the 8.8 in my Dad's 98 Ranger and it's about 57.5" wide and the center isn't offset.
The hard part about getting a ranger rear is finding a 4.0 5 speed truck with a good gear and a trac lok in the salvage yard, every explorer has an 8.8 and 8 out of 10 have a trac lok and 3.55/3.73 or 4.10's.
