Leaking axle seal 8 3/4

Most not all Cherokee's have your basic 8 1/4 Chrysler rear. The thing is have they improved them over the years, or changed them. I'm not trying to hi-jack the thread, but it makes me wonder if there's any truth to the whole "green bearing suck for the street thing." I know 8 1/4 uses c clip bearings, and I think they are ball bearings, just like the new green bearings. Which makes me wonder if buying a rear disc brake kit is silly too, since some late model jeeps have rear discs. I wonder if you just need the correct bearings to swap them ?