Yes, it has been done by several people. I don't know all the details but you do have to replace a lot of parts and I am pretty sure that includes the drive axles. I considered it but after seeing how much it would cost, I dropped the idea. I may still do it someday when it comes time to replace the wheel bearings.
I know one person that did it and decided it was not worth the effort and cost to do it.
If you use the manual locking hub system, the only thing you need to be concerned about on the vacuum system is to plug the hole to the vacuum port to keep the dirt out.
2002 FX4 Bright Red Supercab 4.0 SOHC, manual 5-spd & Tcase, 33" BFG MTs, K&N air filter, Modified air box inlet, Gibson SS cat. back exhaust, Bama flash, Hidden Hitch round receiver, Rear helper air springs, Electric trailer brake controller, Line-X bed liner, WAAG bar with KC lights and Wildernest shell.