It was the power to weight ratio. GTO's weighed more than Firebirds. A plastic tab was installed on the linkage of Firebirds to restrict full opening of the secondaries, limiting HP and was easily defeated.
Insurance purposes and GM edict. 1 HP per 10 pounds vehicle weight.
Pontiac engines were quite under rated though.
Si Vis Pacem Parabellum
1967 Starlight black PMD Engineering 400 Auto 1968 Alpine Blue 400 4 speed 1968 Verdoro Green 400 HO 4 speed 2013 1LE 2SS/RS Inferno Orange Camaro.
