The PO swapped the rear with a 01 f350 with 3.73. Front is still original with 4.10. So no 4x4 right now. He gave me the front axle with 3.73 from the same donor truck. Problem is I don't think I want to do it. Should I find a rear axle with 4.10s and just put that back in or continue the Frankenstein project and put in the front axle? Is it worth the trouble?

If it were mine, I would do whichever is easiest. There's just not a whole lotta difference to worry over.

Find a factory axle and swap it back in. The spring perches on the 01 axles are 1.5" narrower than what your truck originally came with. What that boils down to is poor ride quality. Sell the 01 axles for 1000 and make a little bit of money.

Not sure where ride quality comes to play on any of this unless changing springs or going to solid axle on the front which is still a spring change as well. Then it is a matter of getting everything to work right from two completely different frame setups. I would venture to guess or hope that the PO at least relocated the spring perches to make up for the difference in location, otherwise the springs are being held in a sideways twist.

The rear swaps easier that the front, so I would just get the right axle for the rear and sell the others. The difference in gear ratio is negligible if fuel efficiency or such is any kind of concern.