It's not very common from what I've seen over the past ~12 years of doing this stuff lol, not really sure why tbh they're a dime a dozen. I don't remember offhand how the width matches up with an A-body but for sure at the very least you'd need to cut off the spring perches and weld on new ones (XJs are axle-under-spring, opposite of most applications). I don't know if XJs ever got rear disc brakes though AFAIK they always had teeny-weeny rear drums, might have to grab the brake setup off a Liberty or ZJ/WJ (Grand Cherokee).
Nice part is though the vast majority of XJ 8.25s came with 3.55:1 gearing from the factory.
