I'm working on my wife's 75 Duster 360 (real 360 car)..
The transmission (727) is stumping me because I'm not getting it to kick down like I expect it to. Lots of forums searches and reading tells me that unless it has a Part Throttle Kickdown, I can expect it not to downshift unless wide open.
I have no idea of the origins of the transmission, only that it's clean on the inside (I just dropped and changed the pan & gasket and topped it off while idling hot & in neutral).
Attached is a picture of the numbers on the drivers side housing. J2801542 3548481
I went over this list here : (
http://www.mymopar.com/downloads/transguide.pdf ) and it skips from 3516868 to 3633552
I have no idea of the transmission is original to the car and that's not even a real issue for me.