what 4 speed auto transmissions can i use? 46rh etc

My understanding is the 42/44 transmissions are 904 size and the 46 are 727 size. Also the 42's were used with 3.9 engine, the 44/46's for the 5.2 and 5.9's used the 46rh/re. I'm all read up because my friend is swapping motors and trans. in his Dakota. I also understand the 44rh will stand up to a 5.9 but the 42rh won't last long. They will all bolt up.