73 duster front end swap

if you want the Demon/Dart grille, you need to swap the entire front bolt on parts. 70-72 Demon/Dart bumper, brackets, grille, grille mount panel, valance, fenders, hood and fender splash shields.

If you want the 70-72 Duster grille, you need to swap on the 70-72 Plymouth bumper, brackets, grille, grill mount panel, and hood. The fenders need a tab added to attach the grille panel, but that's a simple fix.

You cannot mix and match Dodge fenders with Plymouth hood, Dodge grilles with Plymouth fenders etc. Its all Dodge parts, or all Plymouth parts.