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The ’66 model year was a watershed year in the history of the Pontiac GTO. Like its larger sibling, the 2+2, the GTO emerged as a separate model series, rather than an option package on a parent line. With that, it reached a new level of maturity and acceptance in the rapidly expanding intermediate performance market. By year three of the GTO, Pontiac had put its full faith in the viability of the muscle-car concept.
Keeping in line with the other GM intermediates of the time, the GTO benefitted from substantial styling revisions. While not a full redesign on a new body, all the exterior sheetmetal was new, and the look was a logical update of the ’65. The ’66 styling retained the stacked headlamps, split grille, hoodscoop, and even slotted taillamps, however, all of those design elements were re-interpreted. The look was fresh and very attractive, yet it was instantly recognizable as a GTO.
The most daring new design cue was the “flying buttress” roofline used on closed models. Though it was shared with the other GM mid-sized cars, it looked especially integrated into the Pontiac version. Pontiac called it “tunneled backlite styling,” and there was no doubt that it was a hit.
For ’66, the GTO looked a bit softer and not quite as angular as the previous year. Regardless, it still featured an aggressive, athletic look, and was every bit as intimidating as before. Though it was visually larger, the overall length only increased 0.3 inch to 206.4 inches, and shipping weights dropped slightly.
The stacked headlamps lost the forward-leaning quality, and in doing so gained some prominence. As it had in ’65, the hood featured a small scoop and was adorned with an arrowhead emblem on its leading The new egg-crate grille design mimicked that of the ’66 Grand Prix. It was blacked-out with a bright chrome surround and turn-signal lamps housed in its confines. The ’66 Pontiac line was the first to use plastic for a grille material, and in doing so won a Hall of Fame Award from the Society of the Plastics Industry for Joshua R. Madden, who was Staff Materials Engineer at the time. Interestingly, the award was presented in 2012.
The ’66 GTO’s bodysides were more sculpted than the previous year, with a more pronounced “Coke-bottle” contour. The lower sections of the body tucked inward, giving the general shape of a bottle laid sideways. The tail of the GTO was unique with tri-slotted taillamps trimmed in chrome. They mimicked the look of a louvered panel and were framed by chrome trim that covered the trailing edges of the rear quarters and deck lid. Pontiac block lettering was placed between them and a GTO badge was placed on the lower passenger side of the decklid.
Some interesting options were also illustrated in the ’66 dealer brochures, including red plastic fender liners that could be removed for cleaning and an 8-lug integral brake/wheel combination, similar to the version used on the full-sized Pontiacs. Unlike the full-sized cars, which used an aluminum drum with a cast-iron liner for the braking surface, the A-car design used an all-iron drum, which added considerable rotating weight and did not dissipate heat very well. That option was dropped, though a few sets were built. None are known to survive.
Minor Updates UnderHood and a New Ram-Air Option
The mechanical side of the equation was essentially a carry-over from ’65 with three significant changes. First, cars delivered to California received a new air injection reaction (A.I.R.)system, which used a belt-driven pump that injected pressurized air into the exhaust ports to promote more complete burning of exhaust gases. The system used specifically jetted carbs and timing to help reduce emissions.
The second change was the adoption of an updated Tri-Power system, which turned out to be a one-year-only upgrade. Traditionally, the center carb on a Pontiac Tri-Power system was a small-base Rochester two-barrel carb, which was the primary carb for normal operation. For ’66, a new intake manifold mounted a trio of large-base Rochester 2GC carburetors. Interestingly, the ’65 power rating of 360 hp at 5,200 rpm with 424 lb-ft of torque at 3,600 was retained for ’66, though it’s very unlikely that power actually stayed the same—the larger center carb flowed significantly more air.
Top-down transit was very much in vogue back in 1966 and there was no better way to do it
Though the ’66 389 Tri-Power had a new intake manifold with a larger center carburetor, th
The third change was the February 1966 introduction of the elusive XS-coded Ram Air 389 Tri-Power. This engine was rated at the same horsepower and torque levels as the other Tri-Power engines. The XS consisted of the same basic componentry as the regular 360-horse engine, but with a new camshaft and valvesprings. The camshaft was assigned part number 9785744 and stamped H. It featured 301/313 degrees of duration and 0.406-inch lift with 1.5:1 rocker arms. Cars ordered with this engine came with the Ram Air pan and related components in the trunk for installation by the dealer. Although the exact number of XS-coded GTOs is unclear, surviving Pontiac engine logs show that 190 engines were built. Further clouding the issue is the fact that the package was also available over-the-counter for dealer-installed upgrades.
The production of ’66 GTOs was the high-water mark for the line, though sales continued to be strong for several more years.
Why weren’t any of the ’66 Tri-Power engines re-rated from 1965, especially the XS engine? It was a matter of getting around corporate edicts. After the delightfully sneaky moves that put a 389 in the ’64 GTO engine bay, everyone else at GM had big-inch engines in their intermediates. In order to keep some sort of control over the divisions, GM’s new edict stated that cars could not weigh fewer than 10 pounds for every horsepower. To prevent that from happening, Pontiac and other divisions began downrating their engines in order to comply with the rulings.
Still, the performance of the GTO was right up there at the top of the heap, though the heap had grown considerably. In addition to the interdivisional cousins -- the Chevelle SS, the Buick GS, and the Olds 4-4-2 -- came some new crosstown rivals, namely the Ford Fairlane GT/GTA and Dodge Charger.
Road-test performance varied wildly depending on the factory-installed powertrain and “preparation.” Motor Trend tested two ’66 GTOs for its May ’66 issue. One was a Tri-Power-equipped, four-speed convertible with 3.55 Safe-T-Track. It ran a 0-60 time of 6.8 seconds and covered the quarter-mile in 15.50 seconds at 93.16 mph. The coupe, on the other hand, was a 335-horse, base-engine car with a two-speed automatic and an open 3.23 rearend. It ran a 0-60 time of 7.5 seconds and a 15.6 e.t. at 90 mph. Traction problems slowed both cars significantly.
On the other end of the spectrum, Car Craft’s XS-engine test car had all the right moves, and with a four-speed, 3.90 Safe-T-Track, and M&H slicks, it ran 14.05 at 99.66 mph. Other tests with race prepping put the GTO deep in the 12s at 110 mph. They made for impressive cover blurbs but were not representative of what a buyer could expect off the showroom floor.
Pontiac even did TV commercial spot shoots with live tigers, something nearly unheard of t
Of the many tie-in promotions that Pontiac initiated, the Thom McAn GTO shoe campaign was
Though tigers were not popular with upper GM management, they were with buyers -- even Tig
Changes in Promotion
The Tiger-themed GTO promotion started off strong in 1966 but soon ran into trouble. GM Board Chairman James Roche was never a fan of the concept, seeing it as an undignified way of selling cars. He let Pontiac management know of his displeasure, but there was no denying it worked. By the summer of 1966, he had enough and ordered the campaign to cease.
It did end, but by that time Pontiac had a lot of other promotional avenues, so it was not a complete loss. This move on Roche’s part represented the beginning of the corporation’s clampdown on Pontiac’s efforts to cater to the market as it saw fit. Pontiac and its ad agency McManus, John and Adams and their man on the account, Jim Wangers, had successfully worked out tie-ins with such diverse companies as Thom McAn (GTO shoes), Max Factor (GTO cologne), AMT and MPC (promo models and kits). The idea was to stretch advertising dollars by working with companies who bought a lot of radio airtime and had good relationships with large retail stores such as Woolworths. They also helped produce some GTO-themed singles that generated radio airplay. Pontiac extended its reach well beyond the auto industry, and as a result was setting sales records.
The production of ’66 GTOs was the high-water mark for the line, though sales continued to be strong for several more years. Pontiac built a total of 96,946 GTOs, including 10,363 Sport coupes, 73,785 hardtops, and 12,798 convertibles. John Z. DeLorean was firmly in charge of Pontiac Motor Division, and things continued to be bright for the duration of his tenure.