thats what im thinking... I had my a rearend swap and the axles were bent. I had one taken out to measure it. This axle wasnt the same as a fox79-93 axle i had it measured against94+axle,99+ axle so im guessing its gotta be a ranger axle. I think you are right about it having to be a 4.0 v6
You need axles from 83-92 4 cyl or 3.0Ranger/Bronco2, drivers side only. also can use the passenger side from 86-97 Aerostar. Cannot use 4.0 Ranger they have bigger brakes and will not work.