OK, after a sh#t ton of reading I managed to get a "budget" suspension in my car. Only thing left to change are the rear end pinion bushings. For a car like mine, that will see limited street use, it seems more logical to go with spherical since I went with the taboo urethane upper bushing. As long as I keep the urethane bushing greased, i feel it shouldn't bind any more than rubber. Now I know I will not be using urethane for the bushing in the differential, but it seems to me it makes more sense to just step up to the spherical. While I don't have quads in now, I will be putting them in.

If you managed to weed through all that, can anyone give me a good explanation why I should use rubber bushings that will, by design, bind, or use spherical, which by design do not.

Just to be clear, we're talking about the mickey mouse ear bushings in the upper rear control arms on the differential.