1976 Dart - ignition switch

That is off.

Here is mine in ACC.

View attachment 1716293518

Note that it is stiff and I had to wiggle the key to get it there. But that's where ACC is.

I meant to check, but my bet is that the "position" you are feeling between off and run isn't a position at all.
You have 4_positions: ACC, OFF (key out), RUN, START. I have 4-positions: ACC (key out), OFF, RUN, START. What you see in my photo is the full CCW rotation. It would seem my lockset is indexed one position CW...