I found that it would be cheaper to buy a low miler used one from a wrecker on Ebay.
In theory, you should be able to swap in a diff from a QDII model. You'll need to replace the diff and half shafts at a minimum, possibly more.I wonder if a different type front diff could be installed to lose the oddball MB one. If a type from another brand jeep would bolt right in. Then a low milage junkyard could be easily had and the LS options would be easily available. On my one legged mustang, I just got a LS out of a GT that had 373. Jacked up the car and in a few hours I was spinning both tires. I only have the v6 but it has the Trac control and that system sucks. The delay waiting for the brake to come on always triggers the engine shut down forcing a crawl. With limited slip, you can just control yourself like we always have. Traction control is for people that cant drive