Installed the linkage kit this past weekend on my '01 XJ w/the 231/AW4/4.0 combination. I was able to get the linkage installed w/out removing the front driveshaft, however doing so would've made it much easier in the long run.
The only additions I made to the kit to make it easier to install was go by the hardware store and pick up some 3/8-24 lock-nuts (not w/the plastic) and some 3/8 washers for spacers. Used a washer on each side of the shift levers (hopefully that makes sense). I had to adjust the end-links for a bit shorter throw to get everything to shift correctly. I didn't have to cut the threaded rod on my application.
Since I rarely ever drive my XJ in anything other than 2Hi and 4Hi this should work out great for me. Only time I ever use 4Low is simply to see if it's working...
It's amazing how complicated and flimsy the OE shift linkage is when you replace it w/something like this linkage kit... which is so 'simple' in design but much more rugged and EASY to adjust.