Well normally I would say swap the body onto a 4x4 frame. As its allot less work than mounting a 4x4 suspension the a 4x2 frame. In your case a 4x4, 4 door, dually frame is hard to come by.
You don't mention what the 79 has for a t case? If its a 205 it would work except the 1 ton trans and t case usually have bigger input / output shafts, bigger yokes, etc.
The front end would work but it would not be correct as it doesn't have the capacity to put true bud wheels on it. Also it wouldn't be a Dana 60 like a 1 ton would have had for a front end.