1st to stop any more confusion. your parts truck is NOT a F350 superduty. It is a F-superduty or also known as a F450
Is your truck a F250 dually conversion or a F350?
What engine was the ZF in front of, if a 460 you are set, if a diesel, you are screwed.
For the clutch pedal, you will need one from a 80-86, the 87-91 will not work
For the rear brakes, just leave your drums on the back(Nothing off the D80 F450 axle will work on your pick up )
Driveshaft i would bet re different length but with your pickup being a C6 it may some how be the same length as a C-n-c