Honestly, I have never tried it. I would get the original unit rebuilt and use it if I were doing it. I'm sure you could convert every thing over but it would hinder your progress if you have to build custom mounts, get new drive shafts built or your modified, and figure out how to mount the shifters and linkages. You're not gaining a whole awful lot switching over, I don't think. Maybe Hummertech can shed some light on the reliability of the older transfer cases versus the newer ones.