I would suggest the F-Body 8.25 as well. Same width as a '65-'67 B-Body.
Still have to move the spring perches, I cut them down the center and break one half off then set the new perch next to it to set the angle before tacking it in place. Then remove the remainder of the old perch and weld the new one up.
Sounds like it is a similar width to the Cherokee one, but probably going to have a taller ratio. I did find one with a 3.21 gear in it, but pretty sure that is the deepest ratio an F-Body came with.
Not saying it is the best swap, just another option.