I've located a replacement for the NP208 on my 86 302/AOD F150. However, this NP208 is mounted on an 85 F150 300/C4 or C6 truck. Are the transfer cases direct substitutes?

 

There are 2 different rear yokes on 208 transfercases. One has bolt on yoke the other has slip yoke. It they are both the same style yes it will fit. If not you can still use it with driveshaft modifications.

 

Yeah, someone gave me the case out of a Bronco - I noticed the rear yoke difference right away; I've got the slip-yoke type. I don't have time/money to deal with getting another driveshaft made at this time, so I gave it back to them.

Thanks, that's what I needed to know.