I was looking on car-part.com for a differential and I hit a block, all these were listed can anyone tell me the difference(aside from the ratios):

9.75" ring gear, 3.55 ratio, tag S918D, Rr disc brks
9.75" ring gear, 3.55 ratio, tag S919D, Rr disc brks
9.75" ring gear, 3.73 ratio, tag S923D, Rr disc brks

10.25" ring gear (7700 GVW), (tags S114H, S115L & S116L), (3.73 ratio)

9.75" ring gear, 3.31 ratio, tag S916A, Rr disc brks
9.75" ring gear, 3.31 ratio, tag S916A, Rr drum brks
9.75" ring gear, 3.31 ratio, tag S916B, Rr disc brks
9.75" ring gear, 3.31 ratio, tag S916C, Rr disc brks
9.75" ring gear, 3.55 ratio, tag S918E, Rr disc brks
9.75" ring gear, 3.55 ratio, tag S918F, Rr disc brks
9.75" ring gear, 3.55 ratio, tag S919E, Rr disc brks
9.75" ring gear, 3.55 ratio, tag S919F, Rr disc brks
9.75" ring gear, 3.55 ratio, tag S933P, Rr disc brks
9.75" ring gear, 3.55 ratio, tag V919A & V919B, (Rr disc brk)
9.75" ring gear, 3.55 ratio, tags S941A & S942A, Rr disc brks

9.75" ring gear, 3.55 ratio, tags V918A & V918B, (Rr disc brk)
9.75" ring gear, 3.73 ratio, tag S923E, Rr disc brks

9.75" ring gear, 3.73 ratio, tag S923F, Rr disc brks