1970–1981 Pontiac Firebird/Trans Am (2nd Gen) Deep Dive

1970–1981 Pontiac Firebird / Trans Am (2nd Gen)

Historical Context and Development

Pontiac launched the second-generation Firebird in early 1970 (the so‑called 1970½ rollout) amid a shifting American performance landscape. The division’s remit was clear: preserve the brand’s performance identity while meeting looming emissions, safety, and insurance headwinds. Built on GM’s F‑body platform shared with the Chevrolet Camaro, Pontiac pursued a more sophisticated, low‑slung fastback aesthetic compared with the upright first generation. The initial design program was led by Bill Porter in Pontiac Studio, with the signature Endura “beak” front and a tight, semi‑flying buttress rear window line giving the car its wind‑cheating stance. John Schinella would later steward mid‑decade updates and approve the now‑iconic hood bird graphic (created with Pontiac’s graphic team, widely credited to Norm Inouye) that debuted for 1973.

Corporate turbulence defined the era: compression dropped in 1971 across Detroit, net horsepower ratings replaced gross figures in 1972, 5‑mph bumpers arrived for 1973–1974, catalysts in 1975, and ever‑tightening emissions controls thereafter. Yet Pontiac kept the faith with torque‑rich big‑cubes—the 455 HO (1971–1972) and the Super Duty 455 (1973–1974) proved that drivability and speed could survive the malaise era. The 1977 facelift with quad headlamps and the “Bandit” film phenomenon vaulted the Trans Am into pop‑culture royalty and sales orbit. Pontiac’s chassis engineering responded in 1978 with the WS6 handling package—larger anti‑roll bars, quicker steering, 8‑inch wheels, and later four‑wheel disc brakes (1979)—pushing the Firebird into genuine grand‑touring territory. Late cars adopted the turbocharged 4.9 (301) V8 (1980–1981), signaling a new path to performance.

Motorsport influence was oblique but real. Pontiac licensed the “Trans Am” name from the SCCA (a per‑car royalty), though the showroom car itself was never a direct SCCA Trans‑Am series homologation piece in this generation. The platform nevertheless anchored Pontiac’s performance image in showroom stock, NHRA classes, and as a halo for the marque’s engineering credibility.

Engines and Technical Specifications

Across its 12‑year arc, the second‑gen Firebird/Trans Am offered a remarkable variety of powertrains. Early cars centered on high‑compression 400s (Ram Air III/IV), followed by the low‑compression but freer‑revving 455 HO, then the legendary SD‑455, and—post‑catalyst—Pontiac’s carefully massaged W72 400 and the Oldsmobile‑sourced 403. The epilogue was Pontiac’s draw‑through turbocharged 4.9 (301) with electronic spark control.

Driving Experience and Handling Dynamics

Even in base form the second‑gen Firebird has a planted, long‑legged gait. A low cowl and broad fenders frame a clear view of the road; in Trans Am guise the shaker scoop nods as you roll the throttle. Early cars carried serious spring and bar rates—1970 Trans Ams were effectively showroom‑stock road‑race cars with a 1.25‑inch front bar, hefty rear bar, fast steering, and sticky bias‑plys. By the late 1970s, Pontiac traded a touch of rawness for control and grip through the WS6 package: 15×8 aluminum “snowflake” wheels, specific bushings, higher‑rate springs, stouter anti‑roll bars, and a quicker steering box. The result is a car that still rides with American suppleness but steps neatly into corners with confidence, the front end keying in far better than stereotypes suggest.

Gearboxes evolved with the times: early 4‑speeds were Muncie M20/M21, later replaced by the Borg‑Warner Super T‑10. Automatics were the Turbo‑Hydramatic TH400 behind big torque and, later, TH350. Pedal weighting is friendly; clutch take‑up is progressive, and the long shift throws feel mechanical rather than vague. The W72 400 responds crisply off‑idle, its Quadrajet transitioning cleanly if properly tuned, while the SD‑455 pulls with an elastic midrange uncommon in the emissions era. The 4.9 Turbo’s draw‑through setup spools to a convincing swell in the midrange, though heat‑soak and conservative spark maps mean it favors sweeping roads to stop‑start sprints.

Brakes were front discs/rear drums across most of the run, adequate with good linings; the WS6’s four‑wheel discs (1979–1981) are a meaningful upgrade in consistency and pedal feel. Tires define the experience: the platform rewards a modern performance radial, which sharpens transient response without wrecking ride quality. Proper alignment (a touch more negative camber and as much caster as the hardware allows) brings the chassis alive.

Performance Specifications

Variants and Special Editions

Trims spanned from sensible to sensational. The base Firebird and Esprit emphasized comfort and style; the Formula mixed understated looks with real go; the Trans Am delivered the full homologation‑special theater.

• Firebird (Base): inline‑6 early on, then small‑V8 options; minimal body addenda; bench‑to‑bucket interior evolution.
• Firebird Esprit: upscale trim, subdued exterior, often luxury‑leaning options; the “Color Bird” series (Sky Bird, Red Bird, Yellow Bird) added coordinated hues and accents in the late 1970s.
• Firebird Formula: performance sleeper with dual hood scoops (non‑shaker), bigger V8s, and handling bits without the Trans Am’s spoilers and flares.
• Trans Am: aero package (front air dam, wheel‑arch spats, rear spoiler), functional shaker, high‑output engines, and the available WS6 handling package (from 1978).

Special editions and key production figures:

Ownership Notes

• Maintenance: Pontiac V8s use hydraulic lifters—no periodic lash setting. Keep the cooling system healthy (brass/copper radiators benefit from proper mixes), and time the HEI ignition (standardized mid‑decade) to factory specs; excessive advance plus today’s fuels can induce detonation on high‑compression early engines.
• Quadrajet tuning: Correct float height, well‑plug sealing, and a crisp secondary air‑valve adjustment transform drivability. A lean stumble is almost always calibration, not carb “defect.”
• Turbo 4.9 care: Oil quality and heat management are paramount. Maintain wastegate/ESC hardware, ensure the knock sensor circuit is functional, and avoid detonation; replace old vacuum lines and check the carb hat and ducting for leaks.
• Chassis: Subframe bushings, leaf‑spring eyes, body mounts, and steering box lash all matter. WS6 alignment specs sharpen response; good shocks (quality gas‑pressure) are the best money spent.
• Rust watchpoints: cowl/firewall seams, lower fenders, rear quarters, trunk drop‑offs, tail panel, and around T‑tops (Hurst hatches in 1976–1977 are especially prone to leaks if drains clog).
• Parts availability: Excellent. Pontiac V8 internals, Quadrajet parts, and F‑body sheet metal are widely supported. Rear disc pieces for late WS6 cars can be pricier but remain obtainable.
• Restoration difficulty: Interiors (dash pads, door panels) and exterior urethane bumper covers require care; correct graphics packages exist for every special edition.
• Service intervals: 3,000–5,000‑mile oil changes (shorter for turbo use), periodic ignition tune (plugs/wires/cap/rotor), coolant every two years, brake fluid every two years. Differential and gearbox oils per factory specification and use.

Cultural Relevance and Market Perspective

The second‑gen Firebird/Trans Am is inseparable from American car culture. The Trans Am’s cameo as the outlaw hero in Smokey and the Bandit turned a regional performance coupe into a national phenomenon. Television cemented the broader range’s profile, most notably with The Rockford Files, whose hero drove a Firebird Esprit—proof the platform could be both suave and usable. Collectors revere the SD‑455 as a high‑water mark of Detroit engineering in the early emissions era, while 1977–1979 Special Editions and 1979’s 10th Anniversary cars carry enduring cachet. Well‑documented SD‑455 cars command top‑tier money in concours condition; W72/WS6 four‑speeds and low‑mile, original‑paint SEs are blue‑chip within the broader range.

FAQs

What is the difference between the W72 400 and the Olds 403?
The W72 is a Pontiac 400 with revised camshaft, ignition curve, and carb calibration—rated 200 hp (1977) and 220 hp (1978–1979, typically with the 4‑speed). It’s torquier off‑idle and responds well to tuning. The Olds 403 (185 hp) is smoother but has siamesed bores and a shorter stroke; most 403 cars were automatics.

How can I identify a real SD‑455 car?
Check the VIN and cowl/engine codes against factory documentation, and look for SD‑specific block numbers, unique round‑port heads, and the correct carb/distributor part numbers. Proper PHS (Pontiac Historic Services) paperwork is the gold standard.

What does WS6 include?
Introduced for 1978, WS6 added larger anti‑roll bars, a faster steering box, specific bushings/springs, 15×8 aluminum wheels with performance tires, and—starting in 1979—four‑wheel disc brakes. It materially improves turn‑in, grip, and braking consistency.

How quick are these cars in stock form?
Representative figures: an SD‑455 Trans Am runs roughly mid‑14s in the quarter; a healthy 1978 W72/WS6 is typically mid‑15s; a 1980 Turbo is mid‑to‑high‑16s. Early Ram Air IV cars are the quickest of the carbureted bunch in period tests.

Are 1979 400 four‑speed cars rare?
Yes. The Pontiac 400 was limited in 1979 and paired with the 4‑speed; production was only a few thousand units, making correct, documented examples desirable.

Known problem areas?
Beyond corrosion, watch for T‑top leaks (especially early Hurst hatches), aging rubber fuel lines and vacuum hoses, worn steering components, and tired rear leaf springs. Turbo cars require vigilant heat management and intact ESC/knock‑sensor systems.

What’s the appeal of the 4.9 Turbo?
It delivers a unique, period‑correct boosted character with respectable midrange torque and grand‑touring legs, especially with WS6. The draw‑through system is simple but heat‑sensitive; diligent maintenance pays dividends.

Value trends?
SD‑455 cars sit at the top; documented Special Editions (1977 SE, 1978 Y88, 1979 10th Anniversary) and W72/WS6 four‑speeds follow. Condition, originality, and documentation drive the delta more than minor option variations.