1970 Buick Mid-Size Cars Fact Sheet
1970 Buick Mid-Size Cars Facts, Figures, and Specifications

The 1970 Buick Gran Sport and GSX were Buick’s muscle cars for 1970. Both were 455 CID monsters
that earned the respect of all.
1970 – Big Inches Make For Performance Boost
The 1970 mid-size Buick received a mild restyle, but the big news was under the hood of the Gran Sport – now with 455 CID and 360 HP.
General Year Information – 1970 Buick Mid-Size Cars
A new look was used for 1970, with crisper lines and more open wheelhouses. The Sweepspear look was retired once again, with horizontal sculpturing taking its place The basic Buick models had a vertically textured grille with a grid overlay. Narrow lower body moldings and wheelhouse bright moldings were used.
NOTE: The Sportwagon station wagon is considered a separate series and is covered in a separate Fact Sheet.
1970 Buick Mid-Size Car Facts – Models Offered
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Series 43300: Narrow lower body moldings and wheelhouse bright moldings were used. Skylark emblems were on the roof sail panels and side marker lamps were rectangular. The Skylark signature appeared on rear fenders. Interiors were spartan with vinyl and cloth combinations on bench seats standard. All-vinyl was no-cost option for the Coupe and an extra cost option for the Sedan. Standard equipment included a host of mandated safety features, including left-hand outside rear view mirror and back-up lights.
Series 43500: The Skylark 350 was identical to the Skylark, except for the addition of 350 emblems to the body and a Buick emblem for the center grille. Interior trim was slightly upgraded.
Series 44400: The plushest intermediate model had a Buick emblem centered in the grille, lower body and wheelhouse moldings and Skylark signatures on the hood, deck and rear fenders. The Custom badge appeared beneath the rear fender signatures. Interiors were done in all-vinyl or Kenora cloth and vinyl. A bench seat was standard, with bucket front seats available for the convertible and coupe.
Series 43437: Buick’s cosmetic muscle car for 1970 was a one-model series. It was a mild-mannered intermediate with the trimmings of the potent GS 455. A textured black grille was used, with hood scoops on the panel above. GS signatures appeared on the left hand grille, front fenders and deck. All-vinyl bench seats in Sandalwood, blue or black were standard. An all-vinyl notch back seat was optional, as were individual front bucket seats. Standard equipment approximated that found on the Skylark Custom.
Series 44637: This was the truly muscular Buick with a new big block V-8 and Hurst-shifted performance transmissions. Functional hood-scoops dumped cold air into the big V-8’s intake. Chrome red-filled lower body and wheelhouse moldings were used with five-spoke 14 x 6 inch chrome wheels standard. A GS 455 emblem appeared on the left-hand blacked-out grille with others showing up on the front fenders and a GS monogram appearing on the deck lid. Standard interior appointments were the same as on the GS.
Series 43437- GSX / GSX Stage 1: The GSX Performance and Handling package, released mid-year, was a $1,100 option on the GS455. The GSX was Buick’s answer to Pontiac’s GTO Judge, Oldsmobile’s 4-4-2 W-30, and Chevrolet’s Chevelle SS 454. It came standard with the 455 CID engine with or without the optional Stage 1 performance engine upgrades. The GSX was equipped as a GS 455 with more options as standard.
The GSX did not appear in the standard model catalog for 1970, however a GSX brochure was made available to the public. Only 678 GSXs were produced in the second half of the 1970 model year beginning in March 1970. and ending in May of 1970. Just 278 were equipped with the standard 455, a further 400 purchasers selected the optional Stage 1 performance package. At 510 lb-ft the Buick 455 produced the highest torque output of any American production performance car.
In 1970, the GSX option was available in only two colors, Saturn Yellow and Apollo White. All GSXs had the distinctive full body length black stripe that crossed over the standard equipment rear spoiler and was outlined in red pin stripes. A large area of the hood was also black with a hood mounted tachometer, and black front “chin” spoiler. Also standard equipment were black bucket seats, floor shifter, wide oval tires, quick ratio steering and anti-sway bars front and rear and a limited-slip rear differential. Some other choices were automatic transmission or four speed manual, Air Conditioning. (See the attached GS 455 and GSX order sheet to determine the differences).
1970 Buick Mid-Size Car Facts – Engines
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- 250 CID I-6 155 HP
- 350 CID V-8 260 HP
- 350 CID V-8 285 HP
- 350 CID V-8 315 HP
- 455 CID V-8 350 HP
- 455 CID V-8 360 HP Stage 1
- 455 CID V-8 400+ HP Stage 2
In-line Six-cylinder: Overhead valves. Cast-iron block. Displacement: 250 CID. Bore and stroke: 3.875 x 3.53 inches. Compression ratio: 8.5:1. Horsepower: 155 @ 4200 RPM. Torque: 235 ft. lbs. @ 1600 RPM. Five main bearings. Hydraulic valve lifters. Valve Timing: Intake 244°, Exhaust: 244°. Valve Lift: Intake 0.3880″, Exhaust 0.3880″. Overlap: 33°. Carburetor: Rochester one-barrel Model 1MV
V-8: Overhead valve. Cast iron block. Displacement: 350 cubic inches. Bore and stroke: 3.8 x 3.85 inches. Compression ratio: 9.0:1. Brake horsepower: 260 at 4600 RPM. Torque: 360 ft. lbs @ 2600 RPM.Five main bearings. Hydraulic valve lifters. Camshaft Duration: Intake 282°, Exhaust 288°, Valve Lift: Intake 0.3818″, Exhaust 0.3890″ Overlap 62°. Carburetor: Rochester 2MV two barrel
V-8: Overhead valve. Cast iron block. Displacement: 350 cubic inches. Bore and stroke: 3.8 x 3.85 inches. Compression ratio: 9.0:1. Brake horsepower: 285 at 4800 RPM. Torque: 375 ft. lbs @ 3000 RPM.Five main bearings. Hydraulic valve lifters. Camshaft Duration: Intake 282°, Exhaust 288°, Valve Lift: Intake 0.3818″, Exhaust 0.3890″ Overlap 62°. Carburetor: Rochester 4MV Quadrajet four barrel
V-8: Overhead valve. Cast iron block. Displacement: 350 cubic inches. Bore and stroke: 3.8 x 3.85 inches. Compression ratio: 10.25:1. Horsepower: 315 at 4800 RPM. Torque: 410 ft. lbs @ 3200 RPM.Five main bearings. Hydraulic valve lifters. Camshaft Duration: Intake 282°, Exhaust 288°, Valve Lift: Intake 0.3818″, Exhaust 0.3890″ Overlap 62°. Carburetor: Rochester 4MV Quadrajet four barrel
Gran Sport 455 V-8: Overhead valves. Cast-iron block Displacement: 455 cubic inches. Bore and stroke: 4.3 x 3.9 inches. Compression ratio: 10.0:1. Horsepower: 350 at 4600 RPM. Torque 510 ft. lbs. @ 2800 RPM Five main bearings. Hydraulic valve lifters. Camshaft Duration: includes ramps Intake: 292°, Exhaust: 322°, Lift: Intake 0.3873″, Exhaust 0.4584″. Overlap 67°. Carburetor: Rochester Quadrajet 4MV
Gran Sport 455 V-8: Overhead valves. Cast-iron block Displacement: 455 cubic inches. Bore and stroke: 4.3 x 3.9 inches. Compression ratio: 10.0:1. Horsepower: 360 at 4600 RPM. Torque 510 ft. lbs. @ 2800 RPM Five main bearings. Hydraulic valve lifters. Camshaft Duration: includes ramps Intake: 316°, Exhaust: 340°, Lift: Intake 0.4070″, Exhaust 0.4584″. Overlap 90°. Carburetor: Rochester Quadrajet 4MV
Gran Sport 455 Stage 2 (Dealer Installed) V-8: Overhead valves. Cast-iron block Displacement: 455 cubic inches. Bore and stroke: 4.3 x 3.9 inches. Compression ratio: 11.0:1. Horsepower: 360 at 4600 RPM. Torque 510 ft. lbs. @ 2800 RPM Five main bearings. Hydraulic valve lifters. Camshaft Duration: includes ramps Intake: 340°, Exhaust: 360°, Lift: Intake 0.4550, Exhaust 0.4800″. Overlap 120°. Intake Manifold: Edelbrock B4B Aluminum, Carburetor: Holley 850 CFM
1970 Buick Mid-Size Car Facts – Chassis Features
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- Wheelbase: two-door: 112 inches; four-door: 116 inches
- Overall length: two-door: 202.2 inches; four-door: 206.2 inches
- Front Track: Skylark and GS 350: 59.0 inches; GS 455: 59.4 inches
- Rear Track: All: 59.0 inches
- Overall Height: Skylark and GS 350: 53.1 inches GS 455: 53.0 inches; Convertible: 53.3 inches
- Tire size: Skylark, Skylark 350: G78 x 14; GS 350: G70 x 14; GS455: G60 x 15 Optional All: H78 x 14
NOTE: Station Wagon (Sportwagon) treated as separate series and information found in a separate Fact Sheet.
1970 Buick Mid-Size Car Facts – Powertrain Options
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- V-8 350 cubic inch 260 horsepower engine
- V-8 350 cubic inch 280 horsepower engine, Optional Skylark, Std GS 350
- V-8 350 cubic inch 315 horsepower engine, Optional Skylark, Std GS 350, when ordered with the “high performance group”
- V-8 455 cubic inch 350 horsepower engine; Standard GS 455
- V-8 455 cubic inch 360 horsepower Stage 1 engine; Optional GS 455
- V-8 455 cubic inch 400 horsepower Stage 2 engine (Dealer installed any GS)
- Four-speed transmission – Optional Skylark and GS 350
- Four-speed transmission – Optional GS 455, standard GSX
- Three-speed manual transmission with column shift was standard on Skylark. Skylark 350, Skylark Custom. and GS
- Three-speed manual transmission with floor-mounted shifter was standard on GS 455
- Turbo-Hydramatic 350 was available with Skylark series and the GS
- Turbo-Hydramatic 400 automatic transmission Optional GS 455 and GSX (with Console)
- Posi-traction rear axle; Optional all except GSX, standard w/3.42:1 ratio
1970 Buick Mid-Size Car Facts – Significant Options
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- Air Cleaner, Heavy Duty
- Air conditioning.
- AM radio.
- AM/FM radio.
- Battery, Heavy Duty
- Carpet Savers
- Console with shifter (requires bucket seats on GS; GS 455).
- Console, full length with Automatic Transmission shifter (requires bucket seats on GS; GS 455).
- Consolette, no shifter
- Convenience Light Group
- Cooling, Heavy Duty
- Cruise Control (auto trans only)
- Electric clock
- Electric door locks.
- Electric trunk release.
- Four-way power seat control (bench seat)
- Four-way power seat control (driver bucket seat).
- Heater, Engine Block
- Instrument group (gauges & tachometer)
- Instrument group, Rallye (gauges & tachometer)
- Padded Set Cushions (standard all bucket seats)
- Performance Axle, Positraction 3.64:1
- Positraction
- Power brakes.
- Power disc brakes.
- Power steering.
- Power windows.
- Protective body side moldings (except GS-GS 455 GSX).
- Rear view mirror map light.
- Rear Window Defogge
- Remote control outside rear view mirror.
- Rim-mounted horn control (N/A with Rallye Steering Wheel).
- Seat Belts, Custom, front and rear GS only
- Seat Belts, Shoulder, front, Coupes
- Soft-ray tinted glass.
- Soft-ray tinted windshield
- Space-saver spare tire
- Steering Wheel, Rallye
- Steering wheel, tilt
- Stereo tape player.
- Suspension, Rallye (performance)
- Tires, Super-wide, (incl Super Sport wheels) G60x15
- Tires, White wall oversize, H78x14
- Tires, White wall, G78x14.
- Tires, Wide Oval Red Line, G70x14
- Tires, Wide Oval White Letter, G70x14
- Tow Master trailering package.
- Vinyl top covering.
- Wheel Covers, deluxe
- Wheels, Chrome plated
- Wheels, Super Sport
1970 Buick Mid-Size Car Facts – Body Paint Color Codes
Click on the Paint Code Name to See the Mix Codes for the appropriate color:
1970 Buick Mid-Size
10 Glacier White-Apollo White | |
14 Silver Mist | |
16 Tealmist Gray | |
20 Azure Blue | |
25 Gulfstream Blue | |
26 Stratomist Blue | |
28 Diplomat Blue | |
34 Aqua Mist | |
45 Seamist Green | |
46 Emerald Mist | |
48 Sherwood Green | |
50 Bamboo Cream | |
52 Saturn Yellow | |
55 Cornet Gold | |
58 Harvest Gold | |
61 Sandpiper Beige | |
63 Desert Gold | |
68 Burnished Saddle | |
74 Titian Red | |
75 Matador Red | |
76 Sunset Sage | |
78 Misty Burgundy |
1970 Buick Mid-Size Car Facts – Current Market Values
1970 Buick Mid-Size Car Facts – GSX Option
GSX package, code WE1 for Gran Sport. Includes: hood-mounted tachometer, Rally steering wheel, front and rear spoilers, outside sport mirrors, power front disc brakes, G60 x 15 tires, 15 x 7 inch chrome spoke wheels, black bucket seat interior, GSX ornament on instrument panel and grille, GSX decals and body stripes, black-finished hood panels; 4-speed, transmission and consolette, heavy-duty suspension, 350 horsepower 455 cubic inch V-8, Rallye Instruments and clock, Rallye Steering Wheel, 3.42:1 rear axle and Saturn Yellow or Apollo White exterior finish ($1196). See Engines and GSX Order Form for more information.
1970 Buick Mid-Size Car Facts – Stage 1 & Stage 2 Options
NOTE:
- The Stage 1 Option consisted of a higher lift, longer duration camshaft, as well as “select fit” engine components, low restriction dual exhausts, performance axle with 3.64:1 gears, heavy duty radiator, and specific “Stage 1” ornamentation. See Engine Section for more information.
- The Stage 2 Option was dealer installed, only and consisted of special cylinder heads, super high-lift, long duration camshaft, Edelbrock aluminum manifold and Holley carburetor – not recommends for street usage. See Engine Section for more information.
1970 Buick Mid-Size Car Facts – Powertrains
- Three Speed Manual Transmission Ratios
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- I-6 and 350 CID V-8: 1st – 2.54:1, 2nd – 1.50:1, 3rd – 1:1, Reverse – 2.63:1
- 455 CID V-8, Optional GS 350: 1st – 2.42:1, 2nd – 1.61:1, 3rd – 1:1, Reverse – 2.33:1
- Four Speed Manual Transmission Ratios
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- 350 and 455 CID V-8: 1st – 2.20:1, 2nd – 1.64:1, 3rd – 1.28:1, 4th 1:1, Reverse – 2.27:1
- Turbo-Hydramatic 350 Automatic Transmission Ratios
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- I-6 and 350 CID V-8: 1st – 2.52:1, 2nd – 1.52:1, 3rd – 1:1, Reverse – 1.93:1
- Turbo-Hydramatic 400 Automatic Transmission Ratios
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- 455 CID V-8: 1st – 2.48:1, 2nd – 1.61:1, 3rd – 1:1, Reverse – 2.08:1
- Rear Gear Standard Ratios
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- I-6: 3-Speed SMT and Powerglide – 3.08:1, Station Wagon All – 3.55:1, Overdrive SMT – 3.70:1, Special Purpose Sedans & Coupes – 3.55:1; Performance – 3.36:1
- 283 CID V-8 195 HP: 3-Speed SMT – 3.08:1, Overdrive SMT – 3.70:1, Powerglide – 3.36:1, Impala and Super Sport Models – 3.36:1, Special Purpose – 3.55:1; Performance (Standard Sedans & Coupes) – 3.36:1
- 327 CID V-8 250 HP: 3-Speed SMT – 3.31:1, Powerglide – 3.07:1
- GS 350 CID V-8 315 HP: All 3.23:1, Optional 3.42:1
- GS 455 CID V-8 350 HP: 3-Speed SMT & 4-Speed SMT – 3.42:1, Performance – 3.64:1, Turbo-Hydra-Matic – 2.93:1, Performance 3.42:1
- GS 455 CID V-8 360 HP (Stage 1): 3-Speed SMT & 4-Speed SMT – 3.64:1, Optional (Dealer installed) 4.10:1 & 4.56:1, 4.88:1
- GS 455 CID V-8 360 HP (Stage 1): Turbo-Hydramatic 3.64:1, Optional (Dealer installed) 4.10:1 & 4.56:1, 4.88:1
1970 Buick Mid-Size Car Facts – Related Document Downloads
Files directly related to the 1970 Buick Mid-Size Line will appear below:
1970 Buick GS 455 and GSX Order Forms
1970 Buick Mid Size Car Print Advertisements
1970 Buick GS & Buick GS 455
AAMA Specifications Sheets
1970 Buick Skylark Custom
AAMA Specifications Sheets
1970 Buick Skylark & Skylark 350
AAMA Specifications Sheets > Soon
1970 Buick GS 455 Stage 1 Road Test – High Performance Cars Magazine
1970 Buick GS 455 Stage 1 Road Test – Motor Trend Magazine
1970 Buick GS 455 Stage 1 Road Test – Hot Rod Magazine
1970 Buick Mid-Size Car Facts – Related Images
Related Images to the 1970 Buick Mid-Size Line will appear below
1970 Buick GS 455 Convertible
The 1970 Buick GS 455 Convertible, especially in Stage 1 form, as shown here, was the most powerful and fasted convertible in the Buick line – ever! 1,416 Buick GS 455 and GS 455 Stage1 convertibles were built in1970. There factory base price of $3,817 likely slowed sales.
1970 Buick GS 455 Sport Coupe
The 1970 Buick GS 455 Sport Coupe, especially in Stage 1 configuration, was one of the fasted 1970 muscle cars. 8,732 were sold, again with their $3,685 base price a detraction, and when adding in the additional $1,196 cost of the Stage 1 option, you would have been looking at one heck of a lot of coin.
1970 Buick GS Sport Coupe
The 1970 Buick GS Sport Coupe was the 350 CID version of the famous GS 455. It was more reasonably priced at $3,479 and with the “performance package”, you would have 315 HP. 9,948 were sold.
1970 Buick Skylark Custom Convertible
The 1970 Buick Skylark Custom Convertible was the only other mid size Buick convertible available other than the expensive GS 455. But pizzazz sold, and as a result only 4.954 were delivered.
1970 Buick Skylark Custom Sport Coupe
The 1970 Buick Skylark Custom Sport Coupe was just a step below the GS 350. Properly optioned, it could be as nice and as fast as the GS version, As a result 36,367 were delivered.
1970 Buick Skylark Custom 4 Dr Hardtop and Sedan
The 1970 Buick Skylark Custom 4 Dr Hardtop and Sedan were Buick’s bread and butter mid size cars. Unfortunately their higher price kept buyers away with 7,113 buying the 4-door sedan and 12,411 going for the 4-door hardtop.
1970 Buick Skylark 350 Sport Coupe
The 1970 Buick Skylark 350 Sport Coupe, regardless of its “350” moniker, had the I-6 as its standard powerplant. With a bit more chrome and a nicer interior, it was a step up from the base Skylark. Available in 4-door sedan configuration as well, sales were 70,918 for the Coupe, and 30,281 for the 4-door.
1970 Buick Skylark 2-door Sedan
The Base 1970 Buick Skylark 2-door Sedan was the only part of the line where a 2-door post sedan was offered. It was the least expensive mid-size Buick at $3,177. 18,620 were delivered.
1970 Buick Skylark 4-door Sedan
The 1970 Buick Skylark 4-door Sedan was the least expensive 40door mid size, but its utilitarian looks and interior did not fare well with the more affluent Buick buyers. As a result, only 13,420 were built.
1970 Buick GS Series Interior
The 1970 Buick GS Series Bucket Seat Interior was very posh, and if equipped wit the console and automatic transmission “horseshoe” shifter was the class of the GM mid sized offereings.