1970 Buick GSX 455

Muscle car powered by Buick 455-cu.in. OHV V-8, 4-barrel, base GSX tune.

1970 Buick GSX 455 hardtop in white; the exterior establishes GSX appearance context but not whether the car has the base 455 or Stage 1 engine

Factory pathway Factory Buick GS 455-based GSX hardtop package

Engine 455-cu.in. Buick OHV V-8, 350 hp and 510 lb-ft in base GSX 455 form

Known 1970 GSX production 678 total GSX hardtops; Hemmings reports 278 with the base 455/350-hp engine

Paint choices Saturn Yellow or Apollo White/Glacier White only; color totals are not asserted here because references conflict

Story

The 1970 Buick GSX 455 was a factory Buick GS 455-based two-door hardtop package, not a dealer conversion. Manufacturer heritage material identifies the car as a 1970 Buick GSX two-door hardtop with a 455-cid OHV V-8 rated at 350 hp and 510 lb-ft. The GSX package added the visual and chassis equipment that separated it from a regular GS 455: a ram-air hood presentation with hood tach, front and rear spoilers, bold GSX striping and ornamentation, sport mirrors, chrome 15 x 7 road wheels with G60-15 raised-letter tires, power front disc brakes, Rallye Ride Control suspension, and the required black bucket-seat interior. The base GSX 455 used the standard 350-hp 455 rather than the optional Stage 1 engine; Hemmings' production breakdown reports 278 base-455 GSXs within 678 total 1970 GSX hardtops. Because color totals differ among secondary references, this page records the factory-limited paint choices and codes but does not assert a color-by-engine production table. Authentication should focus on the GS 455 hardtop VIN/body context, the GSX cowl/body-plate data, black trim 188 interior evidence, paint code Q or 10/10, drivetrain stamps, and documentary evidence such as invoice, Protect-O-Plate, registry records, or build paperwork.

**1970 Buick GSX in Saturn Yellow from the front; stripes, spoilers, and hood treatment are appearance context rather than engine proof**Greg Gjerdingen / Wikimedia Commons · CC BY 2.0

Specs

Car type: Muscle car
Body: 2-door hardtop
Engine: 455-cu.in. Buick OHV V-8 with Rochester Quadrajet four-barrel
Horsepower: 350 hp @ 4,600 rpm
Torque: 510 lb-ft @ 2,800 rpm
Carburetion: Rochester Quadrajet four-barrel

Equipment

GSX hood and body stripes
Hood-mounted tachometer
Front and rear spoilers
Black bucket-seat interior
Rallye Ride Control suspension
Power front disc brakes
G60-15 raised-letter tires on 15 x 7 chrome road wheels

1970 Buick GS 455 Stage 1 engine bay. This is exact optional Stage 1 powertrain context for the GSX 455 range, not proof that every GSX received Stage 1.Mr.choppers via Wikimedia Commons · CC BY-SA 3.0

Linked Parts

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 $51,800

Jul 28, 2026 · Hagerty Valuation Tools · Current guide point
July 2026 #3 good-condition benchmark for the exact 1970 Buick GSX two-door Sport Coupe with the regular 455cid/350hp four-barrel V8. · unknown · good Hagerty showed $51,800 for the exact base-engine GSX configuration in July 2026. This is a configuration guide, not an individual-car authentication, and it must not be presented as a Stage 1 value.
1970 Buick GSX regular 455 valuation
Auction sale $112,000

Feb 22, 2026 · Bring a Trailer
Apollo White base-engine GSX 446370H315456 with a replacement and modified 455, overhauled TH400, changed 12-bolt axle, circa-2005 refurbishment, build sheets, and Protect-O-Plate. · modified · good Bring a Trailer records the $112,000 winning bid. The replacement engine, performance modifications, changed axle, repaint and refurbishment, unknown total mileage, documentation, and seller-supplied description materially limit comparison with original-drivetrain or concours cars.
25-Years-Owned 1970 Buick GSX 455 Coupe 446370H315456
Auction sale $140,800

Jun 29, 2020 · Mecum Auctions
Saturn Yellow base-engine GSX 446370H277942 with matching 455/350 and M21 four-speed drivetrain, 3.42 Positraction, registry documentation, 2007 rotisserie restoration, and correct supporting components. · restored · concours Mecum records the $140,800 completed sale. This chassis also appeared in earlier auctions; only the June 2020 result is normalized. Four-speed rarity, restoration, registry entry, drivetrain representation, component correctness, mileage claim, and consignor-supplied description materially affect comparison.
1970 Buick GSX 455 four-speed 446370H277942
Auction sale $66,000

Sep 19, 2015 · Mecum Auctions
Apollo White base-engine GSX 446370H303738 with matching-numbers 455/350, Turbo 400 automatic, GSX Historical Society documentation, Protect-O-Plate, broadcast sheet, original order sheet, and restoration photos. · restored · excellent Mecum records the $66,000 completed sale. Engine identity, automatic transmission, restoration, factory documentation, power equipment, and consignor-supplied description materially affect comparison; this is not a Stage 1 observation.
1970 Buick GSX 455 446370H303738

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 Muncie M21 4-speed manual
Factory transmission Turbo Hydra-Matic 400 3-speed automatic

Options

Base 1970 Buick 455 four-barrel V8 specification; Stage 1 is a separate engine pathClassic Muscle · Reference illustration

A9 / WE1 GSX with 455 option factory · performance · Base 455 GSX pathway, distinct from optional Stage 1.
AX / WE1 L75 GSX with Stage 1 option optional · performance · Included for context; not asserted for the target trim unless separately evidenced.
H6 / F41 Rallye Ride Control suspension required · chassis
F7 G60-15 Super Wide Oval raised-letter tires required · chassis
C1 Power front disc brakes required · chassis

Production

1970 GSX base-455 transmission and rear-axle referenceClassic Muscle · Reference illustration

1970 Buick GSX two-door hardtop, all engines total · 678 · documented
Base 455/350-hp GSX by engine · 278 · reported
Base 455/350-hp GSX with Muncie M21 4-speed by transmission · 79 · reported
Base 455/350-hp GSX with automatic transmission by transmission · 199 · reported
Two-door hardtop only by body · 678 · documented

Authenticity

1970 GSX power front disc brake and rear drum referenceClassic Muscle · Reference illustration

VIN series/body/year/plant pattern Example pattern 446370Hxxxxxx: Buick GS 455, 2-door hardtop, 1970, Flint · VIN plate near driver-side A-pillar base · fraud detection
GSX cowl/body plate paint and trim Paint Q or 10/10 and black vinyl trim 188 reported for 1970 GSX · Additional cowl/body plate below hood · trim correctness
Engine serial derivative Original 455 engines carry an engine serial number that matches the VIN sequence; base 455 GS/GSX engine-code context is SR for 455/350 hp, while SS is the 455/360-hp Stage 1 code. · On the 455 CID V-8, the engine number is between the two front spark plugs and the exhaust manifold; the production code number is between the two rear spark plugs and the left exhaust manifold. · numbers matching
GSX-specific exterior equipment Hood stripes, body stripes, front spoiler, rear spoiler, hood tach, sport mirrors, GSX ornamentation · Exterior body, hood, grille, rear quarters, rear spoiler, and instrument panel · trim correctness

Still Researching

production Color-by-engine production totals for the base GSX 455 were not verified in a target-specific factory or registry table during this run; secondary sources also conflict on Apollo White/Saturn Yellow totals.
authenticity markers Engine serial and production-code locations for the 455 V-8, plus SR/SS 455 code identities, were added from a normalized Buick reference source; exact transmission stamp/code locations, axle date-code locations, and acceptable casting/date ranges remain unverified from a factory service or parts manual in reviewed references.

Codes & names