The basic Firebirds and GTO ram air actually works more like cold air induction. Cold air adds more charge to the cylinders than under-hood hot air, so you get increased power anyway. The cowl induction inlet of the Chevelle is located in an area of high pressure at the base of the windshield so it works better as a ram air system.
The original 1970 Trans Am scoop was designed to point forward, but at high speeds the ram effect caused the engine to run too lean. (It did actually function as a ram air induction system.) The difference between this and the twin-scoop system is that the shaker's inlet was raised above the boundary layer into the slip stream. Too bad they didn't try fuel injection.
A good loaction for inlet ducts on the first gen bird is just below the front valence, where air pressure is high enough to actually force air into the inlets. I think Olds may have done that on the 442 at one time.
