The rear of the frame on '89-'95(3rd gen) measures 41" O/D.
This is a '90 4x4 oem bumper on an '84 2wd w/4wd bed.
![](http://img.photobucket.com/albums/v33/Snowtoy/For%20Sale/th_84_2.jpg)
It didn't stick out that much to each side. I had to cut and weld the oem brackets for it to fit, but that was to fit the '84's brackets to the '90 bumper. If the warn bumpers's brackets are adjustable, it should fit w/o a lot of effort.
IME, as long as the vehicles are roughly the same size, you can usually get components like bumpers to fit w/o modifying the bumper itself. Last January a buddy and I installed an ARB bumper from a Cherokee on his 3rd gen Runner. We had to modify the brackets extensively and the front of the Runner's frame, but the bumper itself wasn't touched.