Really technical question
 

So we just got a 1970's to 1980's US Air Force Peacekeeper armored vehicle at work. It's based on that generation of 2500 Dodge with an ugly ass armored body put on it. My project leader wants to turn it into a running actor vehicle for scenarios. Currently it has a Dana 44 in the front and a Dana 70 in the rear. We managed to get it running by jumping off the starter but the problem is the gears and the Dana 70 are so worn it just grind its way through movement. It does move, transfer case seems to be fine, but we're pretty sure that the Dana 70 is just beyond mess up. I have a 2003 Dodge Dakota with a Chrysler 9.25 rear is there any possibility I can replace that Dana 70 with the 9.25 and make it work just to run up and down the road?

My direct supervisor really wants to try and get it running but I told him we have to figure out a whole bunch of things like what the spline input is and if the U-joints are just going to line up so we can just attach it and if the internal gear ratios are the same for the front and the rear.

At worst case scenario is there a way to remove the front gearing from The Dana 44 in order to make it just rear wheel drive?

Any information or theories about how to make this work will help me greatly. If I am able to get it working I will try and make a post in my Desert Customs thread

Why not pull rear driveshaft and lock it in 4hi and use front only?

We've talked about that. I work in a desert / mountainous region so I think they want the four-wheel drive to work or at least rear wheel drive since the engine is pushing 9000 lb around

Open that Dana 70 up and see whats going on first. Then decide if you need to rebuild or replace.