I was in a hurry last night when I replyed. The F250 0r F350 you'll need to find with a ZF5speed to put in yours, you'll need one mated to a 300 I6, 302 or 351W, but I haven't ran across one of these trucks with a 302. The best on the ZF5 is you'll get a good bullet proof tranny, you'll have your Granny 1st like your 4spd with the added OD 5th. all The Ford Tcase will bolt up. they all use the same round bolt pattern.
If the ZF5 ain't the way you want to go you can use the NV trannies out of Chevy or Dodge, it's costly to go this way since you'll need addapters. These can be used w/out hydr clutches and use your 4spd bellhousing.
You'll come out way cheasper by finding a F250 or F350 to use as a donner truck so you can use what you need, then sale the rest to make youyr money back. If I was you I'd find a 86-98 F350 4x4 with ZF5speen then swap full 1 ton drivetrain and be done with all upgrading.
Then you'll have one bullet proof 83 with D60 front. Sterlin 10.2 or D70 rearend with ZF5. oooh i can dream..lol