Looks like the 3 speed was the standard offering and both the 4 speed and auto where extra cost options. This is for a Duster though so you would have to do your own research to see if the Dart Sport was the same.
And on the Dusters it was always a 3 on the floor, the bolt action shifter wasn't an option on the Duster 360.
This is all interesting info. But my car was built Jan. 26 00 hr. 1974 and it shows, mechanically sound but the body work is the *****. Runs in paint, quarter panel sloppy rockers not leaded but it’s all factory.