A833 question

If it's actually a '76 model, it is an overdrive transmission. An aluminum main case with a bearing retainer diameter of 5.125" is another indication, but that's not absolute as gear sets can be swapped between those cases.

Brewer's has some more ID info here
Brewer's Performance - Mopar A833 4-Speed Transmission and Component Specialists

and there's an article here that contains a lot of info on the OD transmissions

4 Speed Transmissions transmission