I want to update the front axle in my 64 4x4, to an open knuckle & Disc brakes. I have a 1980 1/2 ton donor truck with all the parts I need, steering, MC, Etc. My question is, the 64 has 3:73 gears, and the 80 has 3:08 gears, is anything internally interchangeable between the two axles? or should I just look for a truck with the correct 3:73 axle that I need? Thanks!