I looked into the whole rear end swap out a while back for a for a project and it ended up being cost prohibitive. It is possible to change both front & rear components with a 1/2 ton. I have seen them done but it would be helpfull to have a donor truck and you are still getting 40+ year old parts. I'm partial to OD's, and have installed them in numerous vehicles. A whole lot less engineering and work than changing all the other components. Like the other guys mentioned there are a lot of choices out there. I had a 66 C-20 with a 292 and 3 sp OD that I drove for 17 years, daily driver, work truck, hauled a camper, and able go anywhere at freeway speeds.
Fred
