[MrPbody]

Firebird in the late '60s was saddled with corporate politics, and the same engines in the A body made more power than those in the F body. The carb was the only REAL difference. Firebirds had a limiter to keep the throttle from openning all the way. A little trick, and they run the same!
But the GTO had class no other performance car of the era had, including the Firebird. And the A body is a MUCH tougher platform for a high horsepower engine. Not many 10 second F-bodies with stock rear suspension., MANY A bodies, including GTO.
For a pure "road car", Firebird wins, especially the mid '70s cars. Not many cars ever made handle as well, and still offer drivability.