Hey, I am in need of help. I have a 2004 f150 new body style, that is pretty clapped. Background of the truck is I traded a 3 wheeler for it and it was in non running condition. I did some work like new front end suspension, power steering pump, and programmed new keys for it. Since then it has been pretty reliable and I have put around 10-12k miles on it. I have taken it on a few 2.5 hour trips and it sails down the road well. 

The problem with the truck is the owner put in 4.10 gears on the rear diff cause he had plans to make that truck his tow truck cause he bought a new one, but never got around to it. I know the guy on a personal level and he starts and stops projects all the time so nothing crazy on that end. 

So with the stock gears being like 3.65 or something like that (i have to look at the door sticker to be 100%, but i know its not 4.10) the 4x4 does not work. I live in Iowa and would like to have 4x4. I thugged it out for about 2 winters and it sucked. 

So I wanted a 2nd opinion on do I thug it out in 2WD and just save up for a new truck or fix the 4x4 in the truck. Either rear end swap the whole truck or try to switch out just the rear diff gears.  I really would like a 4x4 1995 f150 with an inline 6. For me to find something like that though i will have to go to another state where the rust hasn't destroyed them. But in all reality is that even worth the time and energy? Should I look for another decent truck, if so what should i look for? I just want something affordable, reliable and easy to fix. 

Thank you