Alright well this isnt going to be immediate by any means but i have a friend with a 91 YJ that upgraded to full size Axles, Its a 4 cylinder with a Dana 30/35 combo, He offered to give me his gears (not axles just gears) for free, to my knowledge they should be 4:10 (4 cyl, mt), Could at a later time these gear sets be swapped into my MJ Axles? (currently at 3:55), or is there alot more to it than that? I would have a Garage or experienced mechanic do it 1 of these days but is it worth my time to keep these things around if i get them?