I have a 79 f350 with a manual transmission, 205 married transfer case.
I would like to put in a C6auto, can anyone tell me if there is a difference in the length of the drive shafts are will the ones a have work.

 

It will change. I believe it moves back around 1.5". This is the set up I run and love it. Been along time since I've done this probably about 15 yrs ago. On the front driveline if you have big lift and some suspension travel you might have to clearance out the crossmember for driveshaft clearance. I had to on mine. I'm running about 8" suspension lift and my air bags when articulated will make the driveshaft rub. But its a easy fix. Also you have to move the transfer case side mount back also. The speedometer cable will just barley fit on length. Will probably have to order new cable for automatic. I had to do this for mine. Haven't bought the correct plastic gear for my gearing to get correct speedometer reading yet. Usually watch tachometer instead.