I recently picked up a project my dad started but never got to finish. a 65 F250 352 4 speed. Everything is stripped off of the frame and is in a million pieces, The first problem i have encountered is the front differential. Dad had two front differentials (one off the original truck and another off a parts truck) the only problem is the gears are missing out of them and i have no idea where they could be. I have called around and no one seems to have a front differential so the question i pose here is will a front diff out of a 5th gen f250 work on a 4th gen or did they change them with the new generation.

 

First problem I have answering your question is I have never heard anyone refer to a Ford Truck as a 4th or 5th generation . Although I'm new at this I've only been working on and driving these things for about 50 years.

Eric

 

Sorry about that
4th gen 61-66
5tg gen 66-72

 

So you have the front housings with axle shafts and outers, but the differentials are missing the carriers and ring and pinion?

I think up to '75 is a closed knuckle Dana 44. I would contact your local off road shop and let them price you out installing a new carrier and ring and pinion install to match the rear ratio. Off road shops typically do ring and pinion setup and installs all the time and should be able to help you out.