I don't think any Dart with the exception of the Dart Sport came with a "Rally" Dash. They all have the short and wide sweep speedometer. If you compare a Dart dash frame to a 69 Barracuda or 1970 Duster dash frame you will see the opening in the metal is larger (longer towards the steering column) for the Barracuda/Duster.
Dart Sport never came with a rally dash. The only Darts that had a rally dash were the 1970 Dart Swinger 340's and the 1971 Demon 340's. I believe he mentioned he was looking for a rally dash but couldn't find one.