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

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

Historical Context, Development, and the Competitive Set

Launched midway through the model year, the so-called 1970½ second-generation Firebird was Pontiac’s purist take on the F-body. Lower, wider, and far more cohesive than the first generation, it arrived as insurance rates spiked and emissions rules tightened—yet it still delivered some of the era’s most memorable American performance cars. Design was led by Bill Porter’s studio, which gave the Firebird its beaked nose and tightly drawn surfacing; the Trans Am’s functional aero addenda (front air dam, wheel spats, rear spoiler, and the now-iconic shaker scoop) were conceived with high-speed stability in mind. Corporate realities soon intervened: compression ratios were cut for unleaded fuel in 1971, net horsepower ratings replaced gross in 1972, and the 1973–74 fuel crisis upended performance marketing. Even so, Pontiac engineering kept the flame alight with the round-port 455 HO and the homologation-worthy SD-455, then pivoted to chassis sophistication—most notably the WS6 package—when outright power waned.

The Trans Am badge drew lineage (and name) from SCCA Trans-Am racing, where Pontiac had supported efforts earlier in the first generation. Factory-backed road racing faded as GM deemphasized racing, but the street cars continued the theme. The core rivals across the run were Chevrolet’s Camaro (Z28 and later LT/RS-derived offerings), Ford’s Mustang (which briefly shrank into Mustang II territory before regrowing), and Mopar’s Challenger and ‘Cuda (which departed after 1974). By the late 1970s, with Detroit’s power figures depleted, the Firebird’s emphasis on grip and stance made it the de facto performance standard-bearer among domestic coupes.

Engines and Technical Specifications

Pontiac’s V8 family defined the second-gen Firebird’s character. Early cars offered the high-compression Ram Air 400s; 1971–72 delivered the 455 HO with round-port heads and an aluminum intake. The 1973–74 SD-455 was a genuinely special piece with reinforced block webs, 4-bolt mains, unique rods and pistons, and meticulous calibration. Later, the W72 400 returned some urgency to the late-’70s spec sheets, while an Oldsmobile-built 403 handled automatic-trans duties in many states. The final act was Pontiac’s 301 Turbo, a draw-through Garrett setup with hood-mounted boost lights.

Driving Experience and Handling Dynamics

The second-gen Firebird feels fundamentally well sorted: quick steering, a communicative front end, and strong straight-line stability. Early cars (especially Ram Air and 455 HO) deliver the unmistakable Pontiac torque swell, with a long second gear and a shaker scoop that pulses under load. The Muncie and later Borg-Warner Super T-10 four-speeds favor deliberate, accurate shifts over speed; the TH350/TH400 automatics’ firm calibration suits the torque-rich V8s.

By the late 1970s Pontiac had made chassis tuning the headline. The WS6 package (introduced for 1978) brought wider wheels and tires, specific springs and bushings, larger sway bars, quicker steering, and—starting in 1979—four-wheel disc brakes. Period testers widely praised WS6 cars for their grip and composure on real roads; they feel tight and confidence-inspiring even by contemporary standards. Ride quality is taut but not brittle, and body control is notably better than most domestic peers of the day. The Turbo 4.9 trades some throttle immediacy for boost-fed midrange; lag is evident, but once on song, the car pulls adequately while the hood-mounted boost lights do their part for theater.

Performance Specifications (selected, period-typical ranges)

Results varied with axle ratio, transmission, altitude, and equipment. The figures below reflect period-test ranges enthusiasts commonly reference.

Variants, Trims, and Notable Editions

The second-gen line comprised the base Firebird, the more luxurious Esprit, the performance-focused Formula, and the flagship Trans Am. Highlights and well-documented production counts include:

Ownership Notes: Maintenance, Parts, and Restoration

• Drivetrain: Pontiac V8s are robust when kept cool and well-lubricated. Early engines may use nylon-tooth timing gears that age poorly; timing set replacement is sensible during recommissioning. HEI ignition arrived mid-1970s and simplifies tune-ups.
• Service intervals: Traditional 3,000–4,000-mile oil changes (shorter for turbo cars), periodic valve-train and ignition checks, and Quadrajet rebuilds as needed will keep drivability crisp. Turbo 4.9s benefit from meticulous heat management and fresh vacuum/boost hoses.
• Cooling and fuel: Ensure proper shrouds, fan clutch function, and clean radiators. The Quadrajet’s small primaries/large secondaries work superbly when shafts and wells are tight; proper calibration cures most flat-spot complaints.
• Chassis: Subframe bushings, leaf-spring eye bushings, and steering boxes typically show play; WS6-spec replacements sharpen response. 1979 rear disc parts are obtainable but pricier than drum hardware; 1980 WS6/WS7 supply variations mean some cars have drums despite WS6-like content.
• Corrosion: Check cowl-to-windshield seams, rear frame rails, trunk drop-offs, lower fenders, and T-top perimeters. Hurst hatches (early) are more leak-prone than later Fisher hatches.
• Parts support: F-body aftermarket coverage is excellent—sheet metal, interior trim, weatherstrips, suspension, and brake parts are widely available. SD-455-specific internals, early RA-IV hardware, and rare shaker assemblies are costly and scarce.
• Restoration difficulty: Straightforward body-on-subframe construction. Documentation matters: build sheets, PHS (Pontiac Historic Services) packets, and matching-numbers drivetrains meaningfully affect value.

Cultural Relevance and Market Perspective

Beyond the spec sheets, the second-gen Firebird is a symbol. The 1977 “Bandit” black-and-gold Trans Am put the car on bedroom walls worldwide. The Rockford Files made the Esprit a TV regular. Official pace-car duties at Indianapolis (1980) and Daytona (1981) kept the Trans Am in the public eye as performance rebounded in other segments. Among collectors, RA IV, 455 HO, and especially SD-455 cars sit at the top of the tree; well-preserved W72/WS6 4-speeds, Anniversary editions, and correctly trimmed Special Editions follow. Documented SD-455 and Ram Air IV cars have achieved firmly six-figure auction results, while exceptional late-’70s W72/WS6 and special-package cars routinely draw strong five-figure to low six-figure money, condition and provenance dependent.

FAQs

Which second-gen Firebirds are the most valuable?
SD-455 cars (1973–74) and 1970 Ram Air IV Trans Ams lead, followed by low-mile 1971–72 455 HO, correctly optioned W72/WS6 4-speed cars, and limited Anniversary/Special Editions.

What’s the difference between W72 and WS6?
W72 is the higher-output Pontiac 400 engine package (200 hp in 1977; 220 hp in 1978–79). WS6 is the chassis package introduced for 1978 with wider wheels/tires, uprated suspension and steering, and—starting in 1979—four-wheel disc brakes.

How do I tell a Pontiac 400 from the Oldsmobile 403?
The Pontiac 400 has the distributor at the rear and valve covers with 6 bolts each; the Olds 403 has a front-mounted distributor, 10-bolt valve covers, and “403” commonly cast into the block near the cylinder head. Accessory layouts and intake bolt patterns also differ.

Which years offered the SD-455?
1973 and 1974 only, in both Trans Am and Formula (with very limited Formula production).

Did all WS6 cars get rear disc brakes?
No. Rear discs arrived with WS6 for 1979. In 1980, parts constraints created WS7 cars (effectively WS6 suspension with rear drums). Some 1980–81 WS6 cars have drums; check the build sheet and hardware.

How quick is the Turbo 4.9?
Period tests generally placed 0–60 mph in the upper 7- to 9-second range, with quarter-miles in the mid-to-high 16s. It emphasizes midrange torque and highway passing over all-out acceleration.

Known weak points?
Age-related: subframe and leaf-spring bushings, steering box wear, T-top seal leaks (especially Hurst), and rust at the cowl and rear rails. SD-455 parts are expensive; Turbo 301 plumbing and sensors need to be healthy for proper performance.

Manual gearboxes used?
Muncie 4-speeds early (M20/M21), with Borg-Warner Super T-10 phased in mid-1970s. Ratios and clutch specifications varied by year and axle ratio.

What axle ratios were common?
Performance combinations typically saw 3.23–3.73:1 final drives (Ram Air and early 455 HO often 3.55/3.73; W72 commonly 3.23 or 3.42), subject to transmission and emissions calibration.