1964-65 Pontiac GTOs
Complete article at Wikipedia

1964 Pontiac GTO
The first Pontiac GTO was an option package for the Pontiac LeMans, available with the two-door sedan, hardtop coupe, and convertible body styles. For US$ 296, it included the 389 in³ V8 (rated at 325 hp (242 kW) at 4800 rpm) with a single Carter AFB four-barrel carburetor and dual exhaust, chromed valve covers and air cleaner, 7 blade clutch fan, a floor-shifted three-speed manual transmission with Hurst shifter, stiffer springs, larger diameter front sway bar, wider wheels with 7.50 x 14 redline tires, hood scoops, and GTO badges. Optional equipment included a four-speed manual transmission, two-speed automatic transmission, a more powerful "Tri-Power" carburation rated at 348 hp (260 kW), metallic drum brake linings, limited slip differential, heavy-duty cooling, ride and handling package, and the usual array of power and convenience accessories. With every available option, the GTO cost about US$ 4,500 and weighed around 3,500 pounds (1,600 kg).

Most contemporary road tests used the more powerful Tri-Power engine and four-speed. Car Life clocked a GTO so equipped at 0-60 miles per hour (0-97 km/h) in 6.6 seconds, through the standing quarter mile in 14.8 seconds with a top speed of 99 miles per hour (158 km/h). Like most testers, they criticized the slow steering, particularly without power steering, and inadequate drum brakes, which were identical to those of the normal Tempest. Car and Driver incited controversy when it printed that a GTO that had supposedly been tuned with the "Bobcat" kit offered by Royal Pontiac of Royal Oak, Michigan, was clocked at a quarter mile time of 12.8 seconds and a top speed of 112 mph (179 km/h) on racing slicks. Later reports strongly suggest that the Car and Driver GTOs were equipped with a 421 in³ (6.9 L) engine that was optional in full-sized Pontiacs. Since the two engines were difficult to distinguish externally, the subterfuge was not immediately obvious. Frank Bridge's sales forecast proved inaccurate: the GTO package had sold 10,000 units before the beginning of the 1964 calendar year, and total sales were 32,450.

Bobcat
Throughout the 1960s, Royal Pontiac, a Pontiac car dealer in Royal Oak, Michigan, offered a special tune-up package for Pontiac 389 engines. Many were fitted to GTOs, and the components and instructions could be purchased by mail as well as installed by the dealer. The name "Bobcat" came from the improvised badges created for the modified cars, combining letters from the "Bonneville" and "Catalina" nameplates. Many of the Pontiacs made available for magazine testing were equipped with the Bobcat kit. The GTO Bobcat accelerated 0-60 in 4.6 seconds (this 0-60 time is now equalled by the factory 2005-06 GTO with automatic transmission, fuel injection, and no modifications).

The precise components of the kit varied but generally included pieces to modify the spark advance of the distributor, limiting spark advance to 34-36° at no more than 3,000 rpm (advancing the timing at high rpm for increased power), a thinner head gasket to raise compression to about 11.23:1, a gasket to block the heat riser of the carburetor (keeping it cooler), larger carburetor jets, high-capacity oil pump, and fiberglass shims with lock nuts to hold the hydraulic valve lifters at their maximum point of adjustment, allowing the engine to rev higher without "floating" the valves. Properly installed, the kit could add between 30 and 50 horsepower (20-40 kW), although it required high-octane superpremium gasoline of over 100 octane to avoid spark knock with the higher compression and advanced timing.

1965 Pontiac GTO
The Tempest line, including the GTO, was restyled for the 1965 model year, adding 3.1 inches (7.9 cm) to the overall length while retaining the same wheelbase and interior dimensions. It sported Pontiac's characteristic vertically stacked quad headlights. Overall weight increased about 100 pounds (45 kg). Brake lining area increased nearly 15%. The dashboard design was improved, and an optional rally gauge cluster ($86.08) added a more legible tachometer and oil pressure gauge.

The 389 engine had revised cylinder heads with re-cored intake passages, improving breathing. Rated power increased to 335 hp (250 kW) @ 5,000 rpm for the base 4—barrel engine; the Tri-Power was rated 360 hp ((268 kW) @ 5,200 rpm. The Tri-Power engine had slightly less torque than the base engine, 424 [[Foot-pound force|ft·lbf]] (574 N·m) @ 3,600 rpm versus 431 ft·lbf (584 N·m) @ 3,200 rpm. Transmission and axle ratio choices remained the same.

The restyled GTO had a new simulated hood scoop. A rare, dealer-installed option was a metal underhood pan and gaskets that allowed the scoop to be opened, transforming a cosmetic device into a functional cold air intake. The scoop was low enough that its effectiveness was questionable (it was unlikely to pick up anything but boundary layer air), but it at least admitted cooler, denser air, and allowed more of the engine's formidable roar to escape.

Car Life tested a 1965 GTO with Tri-Power and what they considered the most desirable options (close-ratio four-speed manual transmission, power steering, metallic brakes, rally wheels, 4.11 limited-slip differential, and Rally Gauge Cluster), with a total sticker price of US$3,643.79. With two testers and equipment aboard, they recorded 0-60 miles per hour (0-97 km/h) in 5.8 seconds, the standing quarter mile in 14.5 seconds with a trap speed of 100 miles per hour (160 km/h), and an observed top speed of 114 miles per hour (182.4 km/h) at the engine's 6,000 rpm redline. Even Motor Trend's four-barrel test car, a heavier convertible handicapped by the two-speed automatic transmission and the lack of a limited slip differential, ran 0-60 mph in 7 seconds and through the quarter mile in 16.1 seconds at 89 miles per hour (142.4 km/h).

Major criticisms of the GTO continued to center on its slow steering (ratio of 17.5:1, four turns lock-to-lock) and mediocre brakes. Car Life was satisfied with the metallic brakes on its GTO, but Motor Trend and Road Test found the standard drums with organic linings to be alarmingly inadequate in high-speed driving.

Sales of the GTO, abetted by a formidable marketing and promotional campaign that included songs and various merchandise, more than doubled to 75,342. It was already spawning many imitators, both within other GM divisions and its competitors.