The13-56 in my 89 diesel has issues. Since I'm going to have to yard it out and do something anyway I'd like to look into AWD options. I'd really dig having a transfer case with 2WD, AWD, and 4WD options. But what would get me that, survive in my rig, and work.

 

The only route I can think of is an NP203. I guess awd is similar to full time. I just don’t know about bolting it to your trans

 

NP203 is full-time 4WD, as in you can't shift it into 2WD. I think there was a kit available at one time to convert NP203 to part time, but I think that lost you the differential so it no longer could be used in 4WD on pavement (although I could be wrong about that).

To get the features you are looking for you'll need to look at transfer cases out of newer trucks. I don't know what's available, how strong they are or what will bolt up. But I don't think many (any?) 3/4 ton and heavier new trucks have AWD either, so your options might be limited if not limiting.

 

A NP203 would work if you can find the 4X2 adapter kit. I don't know if it would hold the torque or not, but with the kit you would indeed have 4X2/4X4 and AWD. I also don't know if the bolt pattern and input/output shafts are compatible.