3 diffs - which brg kit

[vince1]

My 70 12 bolt 3.07 diff at the very least needs a bearing and seal kit. Rockauto lists quite a few. Why do they have so many? I was going to order USA std gear ZBKGM12T. Is this the right kit for me?

The only good diff I have is a 64 with 3.73 ratio. Eventually I was going to put those parts into the 66 housing that is original to the truck and change out the 4 spd manual for a 700R4. Do all three of these differentials take the same bearings and seals?

Thanks for your help.