Yes, it has been done. Here's some proof...
@Dusterdude72 's car
@moparwedden 's car
@diymirage 's car
Now, what do you need to convert your '74 Dart Sport? That's a longer list, because all of those cars are '70-72 Dusters.
For a '74, you'll need the hood, the entire hood latch panel and support with the latch mechanism, both front fenders (your Dart fenders will not work), the front bumper and brackets, bumper fill panel, and of course the grille, headlight surrounds and parking lights. Depending on the year of the fenders you use you might also need to add mounting tabs for the fill panel and grille. Basically, you need the entire front clip from the doors/firewall forward. It doesn't necessarily have to be a complete '69 Valiant front clip, it can be from a '70-72 Duster. But you'd still need the '69 grille and make a few minor modifications like the cars above.
And then there's an added twist on the front bumper- If your '74 Dart Sport has a shock mounted front bumper, you'll need to add the mounting locations for the non-shock mount bumper brackets that you'll need to use. Early '74's came with shock mounted bumpers and no provisions for the non-shock bumpers. Sometime in December of '73 ('74 model year production), the '74's started coming with non-shock mount bumpers. So if your car has non-shock bumpers, the Valiant bumper brackets will bolt right on. But you still need all the other parts.
