rear end advice

no not women, sorry. someone said my back tires were wobblin around, and being that they are cast aluminum rims i would imagine the axles are bent. im also going through bearings pretty fast so, instead of new rims and tires i want to fix this first. 83/4 with 9 inch drums, but i want to measure before im sure there 9 inchers.

what should i get for a diff? says 10 bolt should i rip apart the axle to check the old one? can i use the old gears depending on condition? im sure i dont need one, but there is not a sure grip in there, i can tell cuz in the snow only one wheel spins, and know that i have hp theres no such thing as traction. looking at this guy http://www.summitracing.com/parts/aub-542051/overview/year/1973/make/plymouth/model/duster

or http://www.jegs.com/i/Powertrax/754/1240-LR/10002/-1

and these axles http://www.summitracing.com/parts/sag-pa5298/overview/year/1973/make/plymouth/model/duster