74 Duster vs 70 Dart?

I'd say build the one that will bring you the most joy doing. If you feel and from your post I think your leaning towards the Dart that you'll have more fun and enjoy wrenching on it then I would go that route. If it is truly is a toss up and you don't care about the resale value, how much time and effort your going to put into it, or who else likes it, then I'd go with the one that would be an easier (more enjoyable, less money) build for you. I love both of those cars and feel they don't get enough love in the hobby and I'm a sucker for a fold down back seat. I will say out here in Southern California you will see, very few but more Darts than Dusters at most shows. The 74's don't get much love because of the big bumpers and think that the masses in the hobby always prefer the smaller bumper cars.

With all that said, I'd build the 74! But I like being the odd car or the not the 1 of 100 at the car show car guy. And they are the cars that draw most of my attention at the shows.

Good luck!