71-72 duster hood for a dart

Those are ‘72 Dart/Demon fenders. It appears you are also missing the hood latch support panel, which is probably why the grille didn’t fit right either.
A Duster hood will not fit with your current fenders.

73-76 Dart fenders are different, they are a single piece and have no provision for a lower valance panel because 73-76 Darts didn’t have one. The ‘70-72 fenders have that fender extension that bolts to the front of the fender, have mounts for the lower valance, and do not have the mounts for the upper header panel (the beak) found on the ‘73-76 Darts.

So as your car sits now, you need a ‘70-72 Dart/Demon hood and a ‘70-72 Dart or Demon hood latch support panel.

Anything other than a ‘70-‘72 Dart hood will also require you to switch the rest of your front clip (fenders, bumper, valance) to match whatever hood you want. But more than likely it would be cheaper to buy a new fiberglass ‘70-72 Dart hood than buy an entire front clip from something else.