Functional hood scoops

The factory hood scoops being functional at all is a pretty big stretch on these cars, especially the 70/71 version. They're too close to the hood to have any kind of "ram air" effect, they're in the boundary layer for the air flow over the hood. Honestly they probably do more to let hot air out than they do to bring cold air in.

With a cold air intake set up you'd be better off running your ducts to the front behind the grille than to any of the factory hood scoops. The '72 scoop might be marginally better than the 70/71 because of its higher profile, but realistically it's still too low for any real air induction. The large flat grille on the other hand catches a ton of air, which is why these cars tend to get light in the front end at high speed.