I did this very thing with my 74 Duster. The core supports are virtually the same. The 70-72 grille is partially supported by a metal bracket that spans across from fender to fender. In stock form, the 70-72 fenders had tabs welded above the headlights to secure the upper grille panel. I had to fab these when I did my car, since I retained the 74 fenders. I used hood pins, so the latch wasn't an issue.