Questiton for you 4x4 folks

[Eyegore]

Is the th350 on a 2wd the same as a th350 4x4? I know the end shaft is different along with the transfer case but is there a difference between the two? I ask since my son is pulling everything off his 80 2wd w/ a th350 and he knows that the trans is in good shape, but the 78 4x4 k10 w/ a th350 he's not to sure of, in fact it could not stay in park so he wants to swap the two.

Any help would be appreciated.

Thanks

Tom