The dart and duster should be the same. As a matter of fact if you look at them there is very little difference between Darts, Dusters, Barracudas, Challengers, Chargers etc.... They are pretty much the same except for compnent locations. For example the location of the starter relay is different but the wiring to it is the same.

The dash wiring is different between models though. Mainly the rally vs non rally wiring harnesses.

The real differences start to appear in the extra's like overhead consoles, power windows, power seats etc but those are rarely if ever seen on those diagrams.