I've got a 91.5 Dodge 4x4 with an automatic and want an NV4500, how much of a pain is it going to be?

It can be done ad there is conversion kits out there. Your best bet is to find a donor truck for all the inside cab and under the hood parts. You will need to find crossmembers and driveshafts elsewhere.

I have the conversion kit in stock along with the transmission. Let me do some measuring tomorrow to see if you need any driveshaft modifications. Off the top of my head i dont think you do but i do know you need to change the input on your t-case from a 23 spline to a 29 spline and also bore out the case on your t-case because the 5spd t-case uses a bigger input bearing in the t-case. Like Bill said you may need to find a donor truck for the stuff inside. If you cant find it i might have some places that have it. I believe the crossmember is the same but i will check it all out tomorrow and Pm you.
Dan

Ramwelding you have a pm.

Dan

thanks for all the suggestions