Yeah, that's about what I was expecting, just wanted to make sure there wasn't a hidden thing I was missing. The one I found is outta of a jeep cherokee, so will most likely take a bit more work.
An A body rear is 52 5/8" flange to flange, so if it's close it will work. The spring perches are bound to be different so you would have to address that issue and get the other things I mentioned.
Like I said to save money if you're on a budget, you can elongate the holes in the shock plates you have and possibly use them. Buy new U bolts and spring perches and weld those on (don't forget pinion angle!) and then you will have to deal with the emergency brake, I'm not familiar with the rear out of a Jeep, it might be the same or it might be different.
All in all I don't believe it will be a direct swap. You might be better served to find one out of an A body unless you can do a lot of the work yourself.
