One trans is electronic, the other hydraulic. 47re electronic, 47rh hydraulic... I believe both are basically a 727 Tourqueflite, but with an over drive on the back.
I dont know much about them, but the 727 was near bullet proof. ive read they can handle 500hp without too much trouble or mild modifications. BUT, that doesnt really help you much...
There is a guy down the road with a newer Ram, goin on about how it makes more power than a semi... but he is on something like the 5th transmission. Its pretty easy to get those engine making big HP, but then you have to start putting some serious $$$ into the transmission to hold up to it.
I believe those years trucks still had dana 60 up front, and 70 or 80 rear for a dually.
So then... uhh, whatcha buildin?