Demon front end.

You'll need the hood, fenders with extensions, valence, and hood latch support assembly. It is also a good idea to pull the front turn signal pigtails. The light sockets are different between the 72 and 73 models for certain. If the 74 does not have pigtails to the front turn signals, you'll need to pull the front wiring harness that includes the lights. Otherwise, be prepared to improvise.

The fenders on the 73 & later have a vertical front end. The 70-72 Dart/Demon have shorter fenders, that are straight, capped with extensions that tilt towards the wheels at the bottom.

Any 70-72 Dart or Demon that has good front sheet metal will make a good donor. The 72 grille and headlight surrounds are unique to that year. I'm not aware of any difference between the 70 & 71 models.