You can easily change the output shaft. You obviously need a 22 spline output shaft. After that it is a fairly easy swap. Remove the end case of the tranny, remove the retaining ring on the viscous coupler, remove VC, remove retaining ball if it hasn't fallen out, remove t-case output shaft. Swap in the other shaft, and reverse. However, if you need to get an output shaft, which is arguably harder to get, I'd just source a transfer case. Since you have to pull the old one out anyways, it will just produce less work. Although output shafts are much smaller and cheaper to ship.