i custom ordered my 2001 f250 and ordered it with manual x-case because of all the problems the automatic was having, but only bad part was you had to get out to lock the hubs. well, now i got it hooked up to where the hubs are locked and unlocked from the cab from a press of two switches, one to lock and the other to unlock the hubs. everything is factory parts except the pushbutton witches. its the same concept the GEM module does to the vacuum solenoid.
if any of you are interested in making your hubs automatic, let me know i will show you how.