Swap body or axles?

[cooperhw]

Hi guys,
I am usually over in the 67-72 forum but I have a few swap questions I want to direct towards you Square Body Gurus.
I have an 81 3/4 ton 4X4 that the body is ok on. Everything else great. I just bought an 85 3/4 ton 2 wheel drive that the body is fantastic on. Glass, interior, doors, everything. The reason I bought it was it was so straight and the exact same yellow with white roof as my 81.
My 81 has always just been my ranch truck I leave at my cabin for when it snows and such. I am thinking how would be the best avenue to put these two together?
Will the 4X4 axles bolt underneath the 2 wd chassis? from what I am reading it sounds like swapping the cab, bed, and nose would probably be my best route?
Another question; I acquired a straight 4X4 1/2 ton short bed chassis about a year ago. Would my 3/4 ton long bed axles bolt onto the 1/2 ton short bed frame? I was originally planning to make a short bed 3/4 ton 4X4 out of my parts, but kinda leaning towards leaving it long bed.
What are your thoughts on easiest, best, etc.
I have a project "Meet Homer" in the 67-72 projects and builds forum. You can tell by reading it that I am no stranger to putting in the time or doing the work, but really don't know what will swap on these with the least amount of hassle.