Back to basics...A couple questions on my New A body!

Here are the basics. None of this is absolute so someone may be able to contradict.
Dart Lite and Feather Duster both received alum sub-structure to hood and deck lid. All were /6 with choice of a 904 torqueflite, or manual transmission. Manual trans normally meant 4 speed Overdrive, with aluminum case, but my car contradicts this.... Mine is 3 speed. It also has the code for 3 speed on the options tag. So apparently nothing is set in stone.
Mine is 4wheel DRUM, no power assist. It has NOTHING in options, no air, etc. AM radio. Bench Seat. 2 speed wipers. 7.25 rear end (gears TBD)
I have tried to further decode the tag, but most of the decoder/sites go up to 72 or 73. A FEW of my codes show up, but since mine is a 76, I am not sure if they still carry