supersize this pic | naca airplane scoops

While hoods scoops were a part of the GTO since the first model in 1964, the 1973 model year brought a unique change to this feature. In 1973 the GTO hood scoops were the NACA-style once used on airplanes.

Most 73 GTO literature (including Pontiac's) erroneously refer to these scoops as "NASA" (National Air and Space Administration) scoops. They are actually NACA (National Advisory Committee for Aeronautics) ducts, so named for this 1947 airplane feature that was popular on racing cars in the early 70s.

Although these hood scoops were optional on the Grand Am of that year, few were ordered that way making the 1973 GTO the only production car to ever use this strange feature. It's the most distinguishing feature of this car. Pontiac prepared 73 GTOs with the 455 cid engine for Ram Air, only to drop the option and temporarily offer a Ram Air package through some dealers.

To the left: These scoops are nonfunctional at present because there are two rubber inserts blocking the openings. I have it on high authority (see Milt Schornak below) that only one RAM AIR 73 GTO was ever built (as a prototype) and is still in existence.

Ram Air works on the principle of having a functional hood scoop which "rams" colder, denser air into the carburetor for a slight performance boost. The outside (ramed) air is 30--80 degrees cooler than the air under the hood so it contains more oxygen. To actually "ram" the air, a special foam "tub" has to be fit between the inside of the hood and around the carburetor setup.

There were actually four production Ram Air packages developed during the GTO years (Ram Air V was in development, be never made available to the public.) Each Ram Air development, in addition to actually ramming the air, had a special camshaft, wider exhaust ports, stiffer valve springs, forged pistons, or other mechanical enchantments. You can still see "RAM AIR" on hood scoops of late-model Pontiac Trans Ams.