I did pull a Durango box some years back for this swap. I did rebuild it. I did look at a lot of the threads out there. Yes, a lot of misinformation and I hope not to add to that. I think there are two versions of that gear box. A regular and a snow plow version. So, different ratios. Also, one of the threads said to shorten an internal part. There is an aluminum 'plug' inside the end cap. I did turn off the 3 prongs of it, as to some instructions in a thread. Again, I have not run this box. I was going to put it in my '00 XJ, but the stock box is doing well for the 2" lift and 31's. My other XJ is on 32's or 33's. Also, I need to get a spacer for it. It will probably go into my '88 Comanche.
On that XJ, I did get a cracked frame. Not good. I just had the frame welded up. I didn't want to put more money into it, as I'm doing other builds. The '00 did get frame stiffeners. They do make a difference in handling.
As to that, I don't know if you have a steering box brace or not. I like my Ironman steering box setup. For some reason, I think I have a Durango spacer on my '98 XJ. That or bent frame is why I could not get the shaft bearing for the Ironman steering brace on. Need to slot some of the holes, I think he says that in his instructions.
Also, I'd look at a trackbar brace. Stinky Fab, Ironman and RE have them. They are set up for their trackbar bracket. Also, I think Northridge has one. Also, I'd check out Alpine. There was a thread on hidden winch bumpers a month or so back. I saw in one of the pictures, Alpine had a trackbar brace. More like a truss. I do have Stinky's on my '00. I do have RE and Ironman's and they will go into some other builds.
Also, a gear box I've been looking at is the SJ/YJ gear box.