Can you go into more specifics about what you plan to do? I'm afraid you may be creating more work than needed!!!
I have several things I am looking at doing so that is why it all sounds so broad right now.
Some history: I took pictures of the very rusty undercarriage of a van from Salt Lake City to our usual mechanics. They were under the impression that reviving the van would end up costing me over $15,000 in the end, and suggested I consider converting a 2wd to 4x4 myself. I actually mentioned your (Ujoint's) kits and they thought I could find old vehicles to take parts from cheaper than the price of a kit. (A kit, by the way, was one of my original ideas since 2wd vans are so much easier to find, but finding a shop to help with the work turned out to be difficult.)
I have found several '96+ Ford E250 and E350 4x4 vans with bodies and/or engines that aren't what I want, but are cheap enough that I started to wonder if they would be worth it just for the 4x4 components. When I called our shop to ask about having them help put the 4x4 components from a donor vehicle into another van, the guy I spoke with did not make me confident in their abilities. So I started thinking about how to leave 4x4 components mostly intact on the frame.
One 1996 E250 I looked at has been converted to run only on propane (which is annoying) and it has a sliding door (which I don't want). Would it at all be reasonable to pull off the body in order to either switch out the engine or convert the original one back to gas and replace the propane tank with the gas tank that should be there? I would get the replacement engine, gas tank, and a new body with barn doors from a donor van.
I was under the impression that Fords were relatively easy to do body swaps on and that having the body off the vehicle made repairs cheaper to do. Perhaps I am getting far too creative and just need to wait for the right van. Either way, though, somebody is going to have to work on my 4x4 van once I get it and I can't figure out where all the 4x4 vans I see around town are going to get worked on.