Towing

What would be the maximum tow weight of a 2016 f250 6.7 diesel crew cab 4x4 for a 5th wheel

Along the lines of what others have said.....a 3/4 ton truck is limited to around 2800-3000 lbs of wet pin weight (not dry).
This equates to 5th wheel rv trailer in the 12k-13k max wet weight range.

If your F250 has the optional camper package or heavy service package.... it has the same suspension as the F350 srw truck. The rest of the truck is the same (frame/chassis/engine/tranny/axles).