You'd have to swap more than just the hood and grille. You could use a 70-72 duster hood, but you'd need to swap the grille, hood latch panel, lower grille to bumper filler panel, and bumper. The grille swap would take adding some brackets too I believe if you keep the '74 fenders, but that's not a big deal.
The only other swap that would keep that fenders would be a 67-69 valiant, but you'd still have to swap everything listed above for that one too.
The problem is that the 73+ duster stuff has a peak in the middle of the grille, filler panel and bumper, so you really can't re-use those parts with the earlier stuff which is flat.