measure the perches to be surest, but all the other parts swap, have the same thread pitch, etc.

it's almost that simple to remove the gearset - the axle shafts need to be backed out.

pull the brakes, undo the bolts at the backing plate, slide the axles back. unbolt the driveshaft, kick it loose, undo the bolts holding the 3rd member, kick that some more, try not to drop it as you wrestle it out. installation is the opposite of removal.

i set a milk crate or a cinder block up under where the third wants to fall out, gives a stopping point in hoisting it out and back in.

you're right, no gear setup needed provided it matches the front.

you don't just want to get a full-float diamond axle and be done with it, huh.