To many, the start of the classic "muscle car" era is often dated as the minute the first 1964 Pontiac GTO was built. And soon thereafter every other American auto manufacturer was stuffing high-horsepower V-8 engines into mid-sized car platforms.
But the Pontiac offering was different. It sported attitude - and a bigger V-8 that the competition, plus hood scoops, dual exhausts, Hurst shifter, and sporty trim. The name GTO itself stood for "Gran Turismo Omologato," (in Italian, meaning Grand Touring Homologated) which in layman's terms proudly pronounced the Pontiac as accredited for the lofty GT racing circuit. So the GTO was arrogant, and it would remain so throughout its 11-year life in the 60s and 70s.
For 1966, the GTO had a new and more voluptuous body style - also shared with the Lemans and Tempest models. Not until 1967 would GTO be considered by General Motors to be it's own model, no longer being a trim level and performance option for the mid-sized coupes. The 1966 GTO interior was totally restyled as well, with four pods containing the instrumentation and real wood veneer over much of the dash.
Mechanically, the four-barrel 389 cubic inch engine rated at 335 hp was carried over from the 1965 model, as was the 360 hp Tri-Power option (3 X 2 bbl carbs.) The ultra-rare XS Ram Air package was added mid-year to the Tri-Power set-up which boosted power to 380 hp. A hotter cam, stiffer valve springs and cold-air induction system made the difference, but the Ram Air parts were shipped in the trunk and had to be installed by the owner. A total of 96,946 GTOs were built for 1966 - 73,785 hardtops, 12,798 convertibles and 10,363 coupes with roof pillars. Only 19,045 came with the Tri-Power engine, and further less then 50 were XS-equipped.