GM Muscle Cars, The Beat Goes On!

Muscle Cars, by the strictest definition, are intermediate size, performance oriented models, powered by a large V8 engine, at an affordable price, and Pontiac saw the potential for dropping a big block engine into an intermediate frame and marketing it at a budget price.

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Pontiac got past the GM restriction on this combo by making the GTO an option on the Tempest model, creating one of the hottest and most sought after GM Muscle Cars ever produced.

Wondering what GTO stood for? The answer is, Gran Turismo Omologato or Grand Touring Homologated, which is an Italian term meaning, approved production-based racing car. Now there's a little tidbit of trivia for ya!

It is said that Pontiac started the Muscle Car Era with the introduction of the GTO in 1964 and it fueled the competition between GM, Ford, and Chrysler that would keep the Muscle Car industry thriving for years. The GTO package included the 389 V8, quick steering, dual exhaust, and premium tires. The 389 was rated at 325 horsepower with a single 4 bbl carb and 348 horse with the optional Tri-Power (3 deuces) setup.

The success of the 1964 model prompted Pontiac to improve the GTO for 1965. Front and rear styling were changed with the GTO getting stacked headlights like Pontiac's full size models.

Both versions of the 389 engines were improved producing 335 with a single 4bbl and 360 horsepower running the Tri-Power setup. Pontiac also released an over the counter kit that would turn the decorative hood scoops into the first functional ram-air setup.

Pontiac made the GTO its own model for 1966 and it was restyled again with gorgeous Coke-bottle contours with the roof and taillights receiving the most attention which carried over to the '67 model.

GM banned multi-carb setups in mid 1966 which brought an end to their tri-power setup. But Pontiac unveiled an all new 400 cid enlargement of the 389 cid engine in response, available in economy 255 hp, standard 335 hp, High Output 360 hp and Ram Air 360 horsepower versions.

The GTO was drastically restyled for 1968 and gained GM's new split wheelbase A-body with a 112 inch wheelbase. A big change was the new Endura bumper, which was a rubber bumper that gave the car a bumper-less appearance and a new option was hidden headlights which were so common that most people thought they were standard equipment. The engine choices remained the same but were tuned for more torque at lower rpm.

The GTO was radically restyled for 1970 and received a new front end with four exposed headlamps wrapped in a Endura bumper, new body creases, and a redesigned rear end. The economy engine was dropped, but a new 455 cid engine was added at the end of the 1970 season on the Judge.

A rare option on the 1970 GTO was the Vacuum Operated Exhaust option. With the VOE option, the driver could pull on a knob under the dash and engine vacuum was routed to a diaphragm on each muffler. The diaphragm opened an internal baffle and gave the exhaust an express route through the muffler. The device reduced back-pressure and thus increased power, but it also significantly increased the noise level. Due to the Federal government's increasing restrictions on emissions and noise levels, only 233 GTO's were built with the VOE option.

1972 saw the GTO revert back to an option on the LeMans and LeMans Sport. The Judge was discontinued along with the convertible models and the engine power ratings dropped dramatically as the Muscle Car Era came to a close.

Pontiac created a unique identity for the Firebird, despite using the same front fenders, doors and rear fenders as the Camaro. The Firebird's split front grille, beaked hood, and GTO-style taillights gave this sassy muscle car the distinct Pontiac appearance.

Most buyers wisely opted for one of the available V8 engines. The 326 two barrel was rated at 250 horsepower and a special High Output version of the 326 fitted with a four barrel carb was rated at 285 horse. At the top of the motor food chain was the 325 horse 400 borrowed from the GTO and was available with or without Ram Air.

The Ram Air engine included a hotter cam, stronger valve springs, and made use of functional hood scoops. All V8s came standard with a heavy-duty three speed manual transmission and a four speed manual or two and three speed automatic transmissions were optional. Performance axle ratios up to 4.33:1 were available as well as front disk brakes.

The Firebird underwent minor cosmetic changes for '68, the interior was also revised and the rear suspension was refined with the adoption of staggered shocks in the rear and the use of new multi-leaf rear springs.

The standard 400 engine horsepower rating increased to 330 while the Ram Air engine was rated at 335 horse but was replaced mid-year by the 340 horsepower Ram Air II. The 400 HO engine came with free-flow exhausts and a revised cam when mated to the four speed.

The Firebird underwent a major restyling for the 1969 model year. The front end was redone and the rear end and interior were changed slightly. The Ram Air 400 was renamed the Ram Air IV and was rated at 345 horsepower and ran the quarter mile in 14.1 seconds at 101 mph. In March of '69, Pontiac released the Trans Am Performance and Appearance Package into its repertoire of Muscle Cars.

An all new Firebird was introduced for 1970. The front bumper and grille were molded out of Endura rubber and were painted the same color as the car to give it a bumperless appearance. The sides sported rounded full wheel cut outs without any extra trim. The suspension was revised and a rear stabilizer bar was added.

These aerodynamic pieces were claimed to generate 50 pounds of down-force on the front and rear of the car at highway speeds. The Trans Ams also received a rear facing shaker hood scoop to feed the standard Ram Air II engine.

Optional on the Trans Am was the Ram Air IV engine with an increased output of 370 horsepower due to bigger ports, better heads, swirl-polished valves, and an aluminum intake manifold.

A Rare over-the-counter, special order engine called the Ram Air V was an available option that included solid lifters and tunnel port heads and made up to 500 horsepower.

A four speed Hurst shifter was standard, but a three speed Turbo Hydra-matic automatic was available. The Trans Am also featured one of the best tuned suspensions of any Muscle Car produced.

1971 saw little styling change for the Pontiac Firebird other than the addition of high-back bucket seats.

The Muscle Car era was drawing to a close and performance was on the decline and both 400 Ram Air engines were dropped and a new 400 V8 rated at 300 hp was added. Two new less powerful 455 V8s, only available in the Trans Am and rated at 325 and 335 horsepower replaced the Ram Air motors.

The GS package included a more rigid frame, heavy duty shocks and springs, a front anti-roll bar, an upgraded rear suspension, improved braking with enlarged front cylinders, and the 401 cubic inch V8. GM only authorized engines up to 400 cid in their intermediate size cars, so Buick simply named the engine the "400"�. Problem solved!

In 1966 the Gran Sport was an option on the Buick Skylark once again, and they had blacked out grilles, GS badges, and rear facing hood scoops that were non functional. There was a higher horsepower version of the 401, rated at 340 horsepower.

Buick made the Gran Sport its own model in 1967, naming it the Buick GS. The '67 GS had a new engine, which actually produced exactly 400 cubic inches. The new engine ran smoother and had a higher rpm capability. Buick also introduced a new 340 small block as an option for the GS.

Buick made some drastic structural changes on the '68 model cutting 3 inches off the wheelbase, and 4.4 inches overall on the length of the GS and the small block 340 engine was bumped up to 350 cubic inches.

There was a rare dealer installed option package on the "GS 400" called the "Stage 1". It came with a hotter cam, higher compression at 11.0:1, stronger valve springs, and a beefed up tranny. Officially, Buick labeled the Stage 1 at 345 horsepower, but the improvements more realistically brought the horsepower rating to a staggering 390 horse.

1969 brought the Stage 1 and Stage 2 packages, listed at 345 and 360 horsepower respectively. The hood scoops also became functional adding even more power to the street stomping GM Muscle car.

1970 brought the baddest Buick GS ever to roll off the line. GM finally lifted its corporate ban of engines larger than 400 cubic inches in an intermediate body and Buick responded by stuffing a brand new 455 big block into the restyled GS.

The 455 not only had more displacement than the 400 ci, it had bigger valves, and a hotter cam and was hooked up to cold air induction through functional hood scoops. Buick claimed this amounted to 360 horsepower, but it was likely more than 400 horse and went from 0-60 in 6.5 seconds, and ran the quarter mile in 13.8 seconds at 101 mph. The 350 V8 also received a significant increase in horsepower bumping it up to 315 horse, which isn't bad for a small block.

Buick also introduced the GSX package, which added front and rear spoilers, contrasting body stripes, meaty tires, a hood mounted tach, and a heavy duty suspension. All this added up to the GS being one of the ultimate GM muscle cars of all time.

This addition to the long line of GM Muscle Cars was named the 4-4-2, signifying the engine's 4 barrel carb, 4 speed tranny, and dual exhausts.

But in 1965 the 330 engine was replaced with a new 400 cid, generating 345 horsepower and the name now signified the 400 cubic inch engine, 4 barrel carb, and dual exhausts. The package included a heavy duty suspension and clutch, fat tires, and 442 badges.

In 1966 the 400 cid engine was tuned to generate 350 horse, and the introduction of Oldsmobile's tri-carb option boosted output to 360 horsepower. A long list of other options were available including five different transmissions and eight different axle ratios.

Handling remained top-notch due to suspension upgrades and the 442 was again proclaimed as the most balanced of the GM Muscle Cars. Olds also quietly made available a new performance option only for the tri-carb engine known as W-30 that consisted of an air-induction system, and internal engine modifications.

GM then banned the Tri-Carb set-up in 1967, so the W-30 package now included a hotter cam, heavy duty springs, and a "forced air induction system" that included an air induction air cleaner that had huge hoses connecting it to special air induction slots above and below the parking lights.

The Hurst/Olds also featured "Force Air" systems and Turbo Hydromatics with Hurst Dual-Gate shifters. The Hurst/Olds did 0-60 in 5.4 seconds and ran the quarter mile in 13.9 sec at 103 mph.

The W-30 option returned in 1969 with its Force Air induction, and below bumper intakes. This was joined by the W-31 package, which incorporated a 350 cid small block with a special carb, valves, and camshaft.

The Hurst/Olds also returned, with outrageous hood scoops and a slightly detuned 455 engine now producing 380 horse.

The Hurst/Olds was dropped from the lineup in 1970 and wouldn't reappear until '72, but only as a Handling and Appearance Package.

The W-30 hit its performance peak and included a balanced and blueprinted 455 with a hotter cam, performance carb, low-restriction exhausts and the Force Air induction system which utilized two prominent scoops on the hood.

Also included were a lightweight fiberglass hood, plastic inner fenders, aluminum differential carrier and cover, and less sound insulation all to cut weight and improve performance.

1971 saw the beginning of the end for all Muscle Cars, including of course the Olds 442. All engines saw a huge drop in compression ratios and a corresponding drop in the horsepower ratings.

The standard 455 engine dropped to 270 horsepower, while the W-30 dropped to 300 horse even though it still sported the familiar Force Air induction system and the 1970 hotter cam.

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