1973 Pontiac Firebird Trans Am SD-455

Pony car powered by Pontiac LS2 Super Duty 455 V8.

1973 Pontiac Firebird Trans Am exterior in Cameo White/blue graphics; same-year Trans Am context, not individual-car SD-455 proof.

Build pathway Factory Pontiac Firebird Trans Am with LS2 SD-455 option

Engine 455-ci Pontiac LS2 Super Duty V-8, 4-barrel

Rated output 310 net hp at 4,000 rpm; 390 lb-ft at 3,600 rpm

Reported production 252 1973 Trans Am SD-455 cars reported by corroborative registry/reference source

Story

1973 Pontiac Firebird Trans Am SD-455

The 1973 Trans Am SD-455 was a factory Firebird Trans Am built around Pontiac's LS2 Super Duty 455 option rather than a dealer or tuner conversion. The structured records here keep model-line Firebird facts separate from the SD-specific configuration: Tran-Zam's 1973 engine table identifies the LS2 as a Pontiac 455 Super Duty V-8 with 4-barrel carburetion, 8.0:1 compression, 310 net horsepower at 4,000 rpm, 390 lb-ft at 3,600 rpm, VIN engine identifier X, and W8/ZJ block-code aliases.

Transmission coverage is intentionally narrow. The same engine table and option list support M20 four-speed wide-ratio manual availability with the SD-455 and M40 Turbo Hydra-matic availability for 400-and-larger engines, while the M21 close-ratio four-speed row is explicitly not available with the Super Duty 455. Rear-axle coverage is likewise limited to the table-backed 3.42 SD manual listing plus option-table records for Safe-T-Track and Performance Axle availability.

The Trans Am's chassis and appearance records are drawn from the 1973 options table: Y99 Formula Handling Package is standard on Trans Am and includes heavy-duty front and rear stabilizer bars, heavy-duty rear springs and shocks, F60-15 white-letter tires, and 15x7 wheels; power front brakes are also listed as standard on Trans Am. Exterior evidence supports Rally II wheels as standard, Honeycomb wheels as available, and the WW7 Trans Am hood decal as a Trans Am-only option. Color records are restricted to colors the color reference does not mark as unavailable on Trans Am: Cameo White, Admiralty Blue, Brewster Green, and Buccaneer Red.

Production and authenticity claims remain conservative. Classic Car Authority reports 252 1973 Trans Am SD-455 cars and recommends PHS/registry confirmation; that total is recorded as reported, not factory-documented. Authenticity markers in this guide therefore focus on source-backed identifiers: LS2/35X option evidence, VIN engine identifier X, W8/ZJ block-code aliases, and documentation review rather than unsupported originality claims for any photographed car.

**1973 Pontiac Firebird Trans Am side/exterior context from a public show.**Jeremy / Wikimedia Commons · CC BY 2.0 Commons media

Price history

Values

Nominal dollars from original price sheets, auction archives, and approved value references.

Original Price

A verified original price is not yet available for this car.

Market Observations

Price guide value $129,000

Jul 28, 2026 · Hagerty Valuation Tools · Current guide point
Current #3 good-condition guide benchmark for the exact 1973 Trans Am hardtop with the 455cid/310hp four-barrel engine. · unknown · good Hagerty showed $129,000 when accessed on 2026-07-28. This is an unadjusted guide value, not a completed transaction or proof of a particular car's originality.
1973 Pontiac Firebird Trans Am 455cid/310hp
Auction sale $156,000

Dec 16, 2025 · Bring a Trailer
X-code Trans Am 2V87X3N138433 with an automatic transmission, PHS documentation, a prior repaint, and 18k miles shown. · restored · excellent Bring a Trailer records the $156,000 completed sale. The same chassis's April 2025 reserve-not-met listing is excluded as a repeated, non-sale outcome.
1973 Pontiac Firebird Trans Am SD-455 2V87X3N138433
Auction sale $148,500

Jan 18, 2025 · Mecum Kissimmee
X-code Trans Am 2V87X3N138937 with an automatic transmission, matching-numbers SD-455, 63,341 miles shown, and highly original condition reported by Mecum. · survivor · good Mecum records the $148,500 completed sale. Highly original is the auction's description and does not independently certify every component.
1973 Pontiac Trans Am Super Duty 2V87X3N138937
Auction sale $286,000

May 18, 2024 · Mecum Indy
X-code Trans Am 2V87X3N138639 with a four-speed, PHS documentation, matching-numbers SD-455, and a comprehensive restoration completed in 2009. · restored · excellent Mecum displays a $286,000 sold result. This row preserves Mecum's displayed amount; aggregators that report a lower hammer-only result are not separate observations.
1973 Pontiac Trans Am Super Duty 2V87X3N138639
Auction sale $200,000

Dec 21, 2023 · Bring a Trailer
X-code Trans Am 2V87X3N141197 with an automatic transmission, dealer invoice copy, and a two-year refurbishment completed in 2015. · restored · excellent Bring a Trailer records the $200,000 completed sale. The engine rebuild, body-off repaint, and ASC electric sunroof remain material configuration limits.
1973 Pontiac Firebird Trans Am SD-455 2V87X3N141197

Values move with paperwork, originality, options, condition, venue, and body style. High bids and guide values are labeled separately from completed sales.

Reference records

Options, Colors & Components

Source-backed details for trim, chassis, production, and authenticity.

Transmission

Factory transmission M20 4-speed wide-ratio manual
Factory transmission M40 Turbo Hydra-matic 3-speed automatic

Options

35X LS2 SD-455 V-8 4BBL optional · performance · Options table lists the SD-455 for Formula and Trans Am; Trans Am price shown as $521.
371 / G80 Safe-T-Track differential standard · chassis · Options table marks G80 Safe-T-Track as standard on Trans Am.
378 / G92 Performance Axle optional · chassis · Listed as available across the model line including Trans Am.
342 / Y99 Formula Handling Package standard · chassis · Listed as standard on Trans Am and includes heavy-duty stabilizer bars, rear springs and shocks, F60-15 white-letter tires, and 15x7 wheels.
512 / WW7 Trans Am Hood Decal optional · appearance · Listed only for Trans Am.
478 / P05 Honeycomb Wheels optional · appearance · Listed as available on Trans Am.

Paint

**1973 Pontiac Firebird Trans Am rear view; same-year deck spoiler and rear graphics context.**Jeremy / Wikimedia Commons · CC BY 2.0 Commons media

11 Cameo White factory · solid
29 Admiralty Blue factory · unknown
48 Brewster Green factory · unknown
75 Buccaneer Red factory · unknown

Authenticity

**1973 Pontiac Firebird Trans Am rear-quarter display image; restoration/context view.**Jeremy / Wikimedia Commons · CC BY 2.0 Commons media

Engine option evidence 35X / LS2 SD-455 V-8 4BBL · Factory invoice/build documentation such as PHS paperwork and option records · fraud detection
VIN engine identifier X for LS2 Super Duty 455 row · Vehicle identification number engine-position decoding · fraud detection
Engine block-code aliases ZJ for 1973 SD-455 manual; XD for 1973 SD-455 automatic · Engine code stamped into the right-front of the block, just below the cylinder head · numbers matching
Documentation review PHS documentation and registry cross-reference recommended · Pontiac Historical Services paperwork and SD-455 registry/reference review · fraud detection
VIN and build-sheet SD sequence 2V87X3 for 1973 Trans Am SD-455 · Vehicle VIN and build sheet sequence; Hemmings also notes Norwood N on a 1973 SD build sheet · fraud detection
Engine partial VIN stamp Partial VIN starts with 2 followed by the last eight VIN digits · Lower-front of the cylinder block, left of the timing cover · numbers matching
SD-455 cylinder-head identifiers 16 casting number on the center exhaust ports with 6H stamped on the head pad · Center exhaust ports and pad below the lower valve-cover bolts · numbers matching
1973 SD-455 intake casting LS2 cast into the lower right-front corner for 1973 · Lower right-front corner of the intake manifold · date correctness
1973 SD-455 Quadrajet carburetor IDs 7043273 for 1973 manual; 7043270 for 1973 automatic · Driver-side rear area of the carburetor body after removing the shaker scoop assembly · numbers matching
SD-455 Turbo 400 automatic identifier PQ-code Turbo 400 for SD-455 automatic cars · Metal ID tag attached to the transmission case above the oil-pan rail; partial VIN on a small vertical pad above the oil-pan rail behind the shift linkage · numbers matching
SD-455 rear axle tube stamps CM for 3.42 axle; GY for 3.08 axle · Front of the passenger-side axle tube · numbers matching

Still Researching

brakes Options table verifies JL2 power front brakes but does not normalize exact front/rear drum-disc dimensions for this SD-455 configuration.
production A reported 252 total was found, but no factory production table by transmission/color was normalized.
authenticity markers Hemmings resolved additional inspection facets for VIN/build-sheet sequence, engine partial VIN location, 1973 block-code usage, SD head identifiers, 1973 intake casting, 1973 Quadrajet IDs, SD Turbo 400 PQ tag, and axle tube CM/GY stamps; distributor numbers, manual-transmission tag/stamp guidance, and factory component date-acceptance ranges remain unverified from parts/service references.

Codes & names