I have done the swap a few times, I will definitely recommend that you really look at the spring pins and hangers on the 4wd chassis. These are greaseable on our trucks, but were rarely greased and are usually shot. The pins and bushings are still available. The other thing is that the 3/4 ton truck will probably have the "shear type" rear cab mount and will most likely be sagging in the back on one side or another or both. These cab mounts can be rebuilt by Steele Rubber, however it is not cheap. The alternative is to remove the rear cab mount perches from the frame of a 1/2 ton and use them, I went that route on the last two I had done. The last thing is to be sure that the T case has good mounting bushings and that bearings are set up right, if the input shaft can get to much play in it and start to work back and forth which will knock out the center of the aluminum cap on the back side.
All in all the swap is really easy between those years, it is just best to check out the suspension and t-case before putting a cab back on it.
Good luck!
