If it this helps, I found a rearend for my 2002 on Craigslist.

 

okay im runing into nothing but problems on this the local dealer is on back order on parts so it wont be for a while to get them. decided to look for one at the junkyard its a 2001 7.3 3.73 limited slip. i have no idea if its a dana or a sterling axle ive looked online alot of them say 4.10 gear not many say 3.73 how much of a difference would it be if i put a 4:10 in it? the rear ends all come from 2000 or a 2001 f250 7.3 the trucks they came from are from a 2000 or a 2001 f250 same as mine. my trucks in the shop right now waiting on me getting a new rear end right now if i went with a 4:10 would i have to buy anything else to get it to bolt right in? found them online for 575 88,000 miles on it

 

If its a 4wd, you need to stay with the same ratio or you have to replace the front gears too so they match. If its a 2wd, you can bolt in the 4.10 with issues, but its going to run the engine RPM's higher for the same speed, on the plus side though it will add to the pulling power of the truck.