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GM A platform (RWD)
Encyclopedia
The General Motors A platform (commonly called A-body) was a rear wheel drive automobile platform
Automobile platform
An automobile platform is a shared set of common design, engineering, and production efforts, as well as major components over a number of outwardly distinct models and even types of automobiles, often from different, but related marques...
designation used from at least 1939 up until 1981. In 1982, GM introduced a new front wheel drive A platform
GM A platform (FWD)
The General Motors A platform was a mid-size car automobile platform designation used from 1982 to 1996. Previously the A body designation had been used for rear wheel drive mid-sized cars....
, and existing intermediate rear wheel drive products were redesignated as G-bodies
GM G platform (RWD)
The General Motors G platform was an automobile platform designation used for mid-sized rear wheel drive cars first from 1969-1972 and again from 1982 to 1988....
.
1939-1948
The earliest reference to the A-body is with respect to the 1939 Chevrolets and Pontiacs, according to the "Standard Catalog of American Cars". The same book also names the Oldsmobile series 60, which dates back to 1939, as being an A-body. While Chevrolet and Pontiac continued to build an A-body from 1949-1958, the last Oldsmobile Series 60 was produced in 1948.1949–1958
From 1949-1958, only Chevrolets (150Chevrolet 150
The Chevrolet One-Fifty, or 150 was the economy/fleet model of the Chevrolet car from 1953-1957. It took its name by shortening the production series number by one digit in order to capitalize on the numerical auto name trend of the 1950s. The numerical designation '"150"' was also sporadically...
, 210
Chevrolet 210
The Chevrolet Two-Ten, or 210 was the midrange model of the Chevrolet car from 1953-1957. It took its name by shortening the production series number by one digit in order to capitalize on 50's numerical auto name trend. The numerical designation '"210"' was also sporadically used in company...
, Bel Air
Chevrolet Bel Air
The Chevrolet Bel Air is a full-size automobile that was produced by the Chevrolet division of General Motors for the 1950–1975 model years. Hardtops in the Chevrolet Deluxe Styleline model range were designated with the Bel Air name from 1950–1952, but it was not a distinct series of its own until...
, Del Ray
Chevrolet Delray
The Chevrolet Delray debuted in 1954 as an optional trim level on the mid-range 210 series of Chevrolet's full-size car. It later became a distinct series of its own.-1954-1957:...
, Biscayne
Chevrolet Biscayne
-Biscayne Fleetmaster:In 1960, a lower-priced, sparsely trimmed version of the Biscayne called the Fleetmaster was produced. Aimed primarily at the fleet market, the Fleetmaster included a lower grade of upholstery than the standard Biscayne and deleted routine convenience items such as a cigarette...
, and Impala
Chevrolet Impala
The Chevrolet Impala is a full-size automobile built by the Chevrolet division of General Motors introduced for the 1958 model year. Deriving its name from the southern African antelope, Chevrolet's most expensive passenger model through 1965 had become the best-selling automobile in the United...
) and Pontiacs (Chieftain
Pontiac Chieftain
The Pontiac Chieftain was an automobile produced by the Pontiac Motors Division of General Motors from 1949 to 1958. Chieftains were one of the first all new car designs to come to Pontiac in the post World War II years...
, Star Chief
Pontiac Star Chief
The Star Chief was a car built by General Motors' Pontiac division between 1954 and 1966.Between 1954 and 1957, the Star Chief was Pontiac's prestige model; the car was easily identified by its chrome star trim along its sides...
, Super Chief
Pontiac Chieftain
The Pontiac Chieftain was an automobile produced by the Pontiac Motors Division of General Motors from 1949 to 1958. Chieftains were one of the first all new car designs to come to Pontiac in the post World War II years...
, Bonneville
Pontiac Bonneville
The Pontiac Bonneville was an automobile built by the Pontiac division of General Motors from 1957 to 2005. It was introduced as a limited production performance convertible during the 1957 model year...
,) were built on the A-body. These cars were moved to the new B Body
GM B platform
The B platform, or B-body, was General Motors' full-size rear-wheel drive automobile platform. It was closely related to the C-body and D-body and was used for coupés, sedans, and station wagons....
shared with some Buicks and Oldsmobiles in 1959.
1964–1967
The A platform was intermediate-sized platform introduced for the 1964 model year for the mid-sized cars of four GM divisions including the FR layout Chevrolet ChevelleChevrolet Chevelle
The Chevrolet Chevelle is a mid-sized automobile produced by the Chevrolet division of General Motors in three generations for the 1964 through 1977 model years. Part of the GM A-Body platform, the Chevelle was one of Chevrolet's most successful nameplates. Body styles include coupes, sedans,...
, Buick Special
Buick Special
In 1962, the Special was the first American car to use a V6 engine in volume production; it earned Motor Trends Car of the Year for 1962. This 198 in³ Fireball was engineered down from the 215 and used many of the same design parameters, but was cast in iron. Output was 135 hp at...
, Oldsmobile Cutlass
Oldsmobile Cutlass
The Oldsmobile Cutlass is a line of automobiles made by the Oldsmobile division of General Motors. The Cutlass began as a unibody compact car, but saw its greatest success as a body-on-frame intermediate car....
and Pontiac Tempest
Pontiac Tempest
The Pontiac Tempest was an entry-level compact produced by the Pontiac Motor Division of General Motors, introduced in September 1960 for the 1961 model year....
. This A-body was used in a wide variety of GM's most famous cars of the muscle car
Muscle car
Muscle car is a term used to refer to a variety of high-performance automobiles. The Merriam-Webster dictionary defines muscle cars as "any of a group of American-made 2-door sports coupes with powerful engines designed for high-performance driving." Usually, a large V8 engine is fitted in a...
era, including the Pontiac GTO
Pontiac GTO
The Pontiac GTO is an automobile built by Pontiac Division of General Motors in the United States from 1964 to 1974, and by GM subsidiary Holden in Australia from 2004 to 2006. It is considered an innovative, and now classic muscle car of the 1960s and 1970s...
, Chevrolet Malibu
Chevrolet Malibu
Malibus and all other Chevelles were completely restyled for 1968 with semi-fastback rooflines on two-door hardtops and wheelbases split to on two-door models and 118 for four-door sedans and station wagons. Engine offerings included a new V8 rated at that replaced the V8 that had served as the...
SS, Oldsmobile 442
Oldsmobile 442
The Oldsmobile 442 was a muscle car produced by the Oldsmobile division of General Motors. It was introduced as an option package for F-85 and Cutlass models sold in the United States beginning with the 1964 model year. It became a model in its own right from 1968 to 1971, then reverted to an...
and Buick GS
Buick Gran Sport
The Buick Gran Sport or GS was a high-performance option package available on a number of Buick models, including the Riviera, Skylark, Century and Wildcat. A special version of one model was given the package's name as its model name....
. From 1964-69, GM Canada produced a special-market version of the Chevelle, which included Pontiac-type trim and unique taillight assemblies. This car was sold in Canada only as the Beaumont
Beaumont (automobile)
Beaumont was a make of mid-size automobiles produced by General Motors of Canada from 1966 to 1969.-History:The Beaumont car grew out of the 1964-65 Acadian Beaumont model, which was based on the contemporary Chevrolet Chevy II , then Chevelle...
.
Initially, when the A-body cars were first introduced for 1964, GM had set a corporate policy prohibiting V8 engines larger than 330 cu in (5.4 l) in these models. However, Pontiac offered their 389 cu in (6.4 l) V8 in the Lemans to create the GTO — commonly considered the first popular muscle car. Though this technically violated the 330 cu in limit, Pontiac got around the rules by designating the GTO as a low-volume option package rather than a specific model. However, the sales success of the '64 GTO led the corporation to increase the cubic inch limit for the A-body cars to 400 cu in (6.6 l) starting with the 1965 model year to open the door for the other three divisions to offer similar muscle cars. The 400 cu in limit for A-body cars, as well as all other GM cars that were smaller than full-sized with the exception of the Chevrolet Corvette, would continue through the 1969 model year.
The A-body cars were the first intermediate-sized cars to be designed with a full perimeter frame and 4-link coil-spring rear suspension, similar to what was introduced on full-sized Pontiac
Pontiac
Pontiac was an automobile brand that was established in 1926 as a companion make for General Motors' Oakland. Quickly overtaking its parent in popularity, it supplanted the Oakland brand entirely by 1933 and, for most of its life, became a companion make for Chevrolet. Pontiac was sold in the...
s and Oldsmobile
Oldsmobile
Oldsmobile was a brand of American automobile produced for most of its existence by General Motors. It was founded by Ransom E. Olds in 1897. In its 107-year history, it produced 35.2 million cars, including at least 14 million built at its Lansing, Michigan factory...
s in 1961 and then all other GM full-sized cars in 1965.
The Chevrolet A-body line also included the El Camino
Chevrolet El Camino
The Chevrolet El Camino is a coupe utility vehicle produced by the Chevrolet division of General Motors for the 1959–1960 model years in response to the success of its rival, Ford Ranchero. Production resumed for the 1964–1977 model years based on the Chevelle platform, and continued for the...
pickup truck.
Two station wagons based on the A-body used stretched wheelbases and raised rear roof sections with skylights. Those included the 1964-1972 Oldsmobile Vista Cruiser
Oldsmobile Vista Cruiser
The Vista Cruiser is a station wagon built by the Oldsmobile Division of General Motors from 1964 to 1977. It was based on the Oldsmobile Cutlass/F-85 model but prior to the 1973 model year it utilized a wheelbase which was longer than that of the Cutlass/F-85 sedan.Unlike most station wagons, it...
and the 1964-1969 Buick Sport Wagon
Buick Sport Wagon
The General Motors Buick Sport Wagon was a mid-size station wagon and a corporate sister of the Oldsmobile Vista Cruiser. Featuring a raised roof and skylights over the cargo and second seat area, this model was an extended wheelbase version of the Buick Skylark station wagon...
.
All A-body cars had a 115 in (292.1 cm) wheelbase except the stretched-wheelbase wagons which had a 120 in (304.8 cm) wheelbase.
1968-1972
All GM A-bodies were completely restyled in 1968. The 400 cu in limit remained. In 1970 the 400 cu in limit was removed, mainly due to Chrysler's domination in the drag racing and muscle car market with larger engines and highest power rated engines available in nearly all models. This led each of the four GM divisions to offer their largest engines: ChevroletChevrolet
Chevrolet , also known as Chevy , is a brand of vehicle produced by General Motors Company . Founded by Louis Chevrolet and ousted GM founder William C. Durant on November 3, 1911, General Motors acquired Chevrolet in 1918...
's 454 cu in (7.4 l) in the Chevelle SS-454, Pontiac
Pontiac
Pontiac was an automobile brand that was established in 1926 as a companion make for General Motors' Oakland. Quickly overtaking its parent in popularity, it supplanted the Oakland brand entirely by 1933 and, for most of its life, became a companion make for Chevrolet. Pontiac was sold in the...
's 455 cu in in the GTO, Oldsmobile
Oldsmobile
Oldsmobile was a brand of American automobile produced for most of its existence by General Motors. It was founded by Ransom E. Olds in 1897. In its 107-year history, it produced 35.2 million cars, including at least 14 million built at its Lansing, Michigan factory...
's 455 cu in in the 442, and Buick
Buick
Buick is a premium brand of General Motors . Buick models are sold in the United States, Canada, Mexico, China, Taiwan, and Israel, with China being its largest market. Buick holds the distinction as the oldest active American make...
's 455 cu in in the GS.
The two-door had a 112 in (284.5 cm) wheelbase; four-door, station wagon, and the El Camino had a 116 in (294.6 cm) wheelbase; and the stretched-wheelbase wagon had a 121 in (307.3 cm) wheelbase.
Also using a variation of the A-body chassis and suspension were the 1969-1972 Pontiac Grand Prix
Pontiac Grand Prix
Picking up where the Pontiac Ventura model left off, the Grand Prix first appeared in the Pontiac line for 1962. It was essentially a standard Pontiac Catalina coupe with minimal outside chrome trim and a sportier interior...
and 1970-1972 Chevrolet Monte Carlo
Chevrolet Monte Carlo
The Chevrolet Monte Carlo was an American-made two-door coupe introduced for model year 1970, and manufactured over six generations through model year 2007. It was marketed as a personal-luxury coupe through most of its history, with the last model version being classified as a full-sized coupe...
— both of which were marketed as intermediate-sized personal luxury cars and coded as G-body
GM G platform (RWD)
The General Motors G platform was an automobile platform designation used for mid-sized rear wheel drive cars first from 1969-1972 and again from 1982 to 1988....
cars. The Grand Prix had a 118 in (299.7 cm) wheelbase and the Monte Carlo had a 116 in (294.6 cm) wheelbase. When the A- and G-body cars were restyled for 1973, the G-body design was renamed the A-special body.
1973–1977
By this time, the American performance car was considered extinct, but these "forgotten years" had some performance left.
- 1973 Pontiac LeMans with the GTOGTOGTO is an abbreviation of:* A gate turn-off thyristor*Geographic targeting order, an order issued by the United States Secretary of Treasury* Geostationary transfer orbit, an intermediate orbit around the Earth...
option and the Pontiac Grand Am — Available with a 400 cid 230 hp V8 which was available with a 3-speed (LeMans, GTO) or 4-speed manual (LeMans, GTO, Grand AmPontiac Grand AmThe original Grand Am was introduced in the fall of 1972 as a 1973 model. It was based on the GM A platform along with other cars such as the Pontiac LeMans, Pontiac GTO, Chevrolet Chevelle, Buick Century, and the Oldsmobile Cutlass Supreme...
) transmission or an automatic (LeMans, GTO, Grand Am), or a 250 hp 455 with an automatic transmission only. Also announced for the '73 GTO and Grand Am was the Super Duty 455 V8, which was rated at 310 hp. Cars magazine tested an SD-455-equipped 1973 Pontiac GTOPontiac GTOThe Pontiac GTO is an automobile built by Pontiac Division of General Motors in the United States from 1964 to 1974, and by GM subsidiary Holden in Australia from 2004 to 2006. It is considered an innovative, and now classic muscle car of the 1960s and 1970s...
and chose it as Car Of The YearCar of the YearCar of the Year is a phrase usually considered to have been invented by Motor Trend magazine in the 1950s for their annual award for best American automobile...
, yet that engine never made it to production in a GTO or other Pontiac A-body, but would be limited to the Firebird Formula and Trans Am. - 1973 Chevrolet Chevelle SS and 1974-1976 Chevelle Laguna S-3 — Offered with 350 small block or 454 big block V8 with up to 245 hp with manual or automatic transmissions. The SS was replaced for 1974 by the Laguna Type S-3 which offered the same engine/transmission offerings as the '73 SS plus the addition of a 400 small block V8, along with a urethane front end surrounding the grillework. The 1975-76 Laguna S-3 featured a more aerodynamic slanted front end but engines were further detuned due to emission requirements and the advent of the catalytic converter, leaving the big 454 V8 unavailable for California cars in 1975 and discontinued altogether for 1976, when the 180 hp small block 400 V8 was the top engine.
- 1973-1974 Buick Century GS — Still available with the Stage 1 455 cid V8 rated at 270 net horsepower, mated to either a Turbo 400 or four-speed manual transmission, the latter transmission reportedly only installed in seven cars that year. The '74 Stage 1 455 was only available with the Turbo 400 automatic and detuned to 245 hp. This engine was also offered on other Buicks in 1974 including the Riviera, LeSabre and Electra.
- 1973-1975 Oldsmobile Cutlass Hurst/Olds W-30 — These were built using 455 cid V8 engines in the W-30 trim. This engine was also available as an option on the Olds 442 of those years along with other Cutlass models.
- 1976 Buick Century Turbo — These were originally built as Indianapolis Pace Car replicas with a turbochargedTurbochargerA turbocharger, or turbo , from the Greek "τύρβη" is a centrifugal compressor powered by a turbine that is driven by an engine's exhaust gases. Its benefit lies with the compressor increasing the mass of air entering the engine , thereby resulting in greater performance...
and carbureted 3.8 L V6, and were faster than the 455 V8 version of that year. There were only a little over 1,200 built. - 1977 Pontiac Can-Am — This car was basically a LeMans Sport Coupe with a Grand PrixPontiac Grand PrixPicking up where the Pontiac Ventura model left off, the Grand Prix first appeared in the Pontiac line for 1962. It was essentially a standard Pontiac Catalina coupe with minimal outside chrome trim and a sportier interior...
interior and a Trans AmTrans AmTrans Am may refer to:* Trans Am , a U.S. post rock band* Trans Am , 1996 debut album* Trans-Am Series, an automobile racing series* Pontiac Trans Am, an automobile* Tranz Am, a 1983 video game...
"Shaker" hood, a one-off wing and a 400 cid V8 rated at 200 hp with federal emissions, or an Oldsmobile 403 with California emissions. Only 1,100 or so of these were made and are getting quite collectible.
1978–1981
All GM intermediate-sized cars were downsized for the 1978 model year in response to CAFE requirements and the increased popularity of smaller cars. The redesigned models were similar in size to the previous X-bodiesGM X platform
There have been two X-body automobile platforms from General Motors. All X-bodies were small entry-level models.-Rear wheel drive:The rear-wheel drive X-body underpinned the Chevrolet Nova and similar cars of the late 1960s and 1970s. It was also the basis for the Cadillac Seville's K platform...
.
The Buick and Oldsmobile were introduced with fastback
Fastback
A fastback is a car body style whose roofline slopes continuously down at the back. The word can also designate the car itself. The style is seen on two-door coupés as well as four-door sedans.-History:...
coupe styles, while the Chevy and Pontiac received notchbacks. Four-door fastback sedan models were also available. An interesting design compromise was non-lowering rear door windows on four-door models. Performance applications include the Chevrolet Malibu
Chevrolet Malibu
Malibus and all other Chevelles were completely restyled for 1968 with semi-fastback rooflines on two-door hardtops and wheelbases split to on two-door models and 118 for four-door sedans and station wagons. Engine offerings included a new V8 rated at that replaced the V8 that had served as the...
F41 and M80, Pontiac LeMans
Pontiac LeMans
The Pontiac LeMans was a model name applied to compact and intermediate-sized automobiles offered by the Pontiac division of General Motors from 1962 to 1981. The LeMans was replaced by the downsized Pontiac Bonneville for the 1982 model year...
GT, Oldsmobile 442
Oldsmobile 442
The Oldsmobile 442 was a muscle car produced by the Oldsmobile division of General Motors. It was introduced as an option package for F-85 and Cutlass models sold in the United States beginning with the 1964 model year. It became a model in its own right from 1968 to 1971, then reverted to an...
and Oldsmobile Hurst/Olds
Oldsmobile Hurst/Olds
Following the success of Hurst components in Oldsmobile's 442 models, Oldsmobile, in collaboration with Hurst Performance of Warminster, Pennsylvania, produced special-edition performance versions of the 442 or Cutlass Supreme, the Hurst/Olds.-1968:...
.
In 1982, with the introduction of the new front wheel drive A-body
GM A platform (FWD)
The General Motors A platform was a mid-size car automobile platform designation used from 1982 to 1996. Previously the A body designation had been used for rear wheel drive mid-sized cars....
, existing rear wheel drive models were given the G-body
GM G platform (RWD)
The General Motors G platform was an automobile platform designation used for mid-sized rear wheel drive cars first from 1969-1972 and again from 1982 to 1988....
designation.
Models of this generation include:
- Buick CenturyBuick CenturyBuick Century is the model name used by the Buick division of General Motors for a line of full-size performance vehicles from 1936 to 1942 and 1954 to 1958, and from 1973 to 2005 for a mid-size car....
(1978–1981) - Buick RegalBuick RegalThe Buick Regal is a mid-size car introduced by General Motors for the 1973 model year. North American production ended in 2004 and began again in 2011. For the 2011 model year, Buick re-introduced the Regal to the North American market, positioned as an upscale sport sedan...
(1978–1987) - Chevrolet El CaminoChevrolet El CaminoThe Chevrolet El Camino is a coupe utility vehicle produced by the Chevrolet division of General Motors for the 1959–1960 model years in response to the success of its rival, Ford Ranchero. Production resumed for the 1964–1977 model years based on the Chevelle platform, and continued for the...
(1978–1987) - Chevrolet MalibuChevrolet MalibuMalibus and all other Chevelles were completely restyled for 1968 with semi-fastback rooflines on two-door hardtops and wheelbases split to on two-door models and 118 for four-door sedans and station wagons. Engine offerings included a new V8 rated at that replaced the V8 that had served as the...
(1978–1983) - Chevrolet Monte CarloChevrolet Monte CarloThe Chevrolet Monte Carlo was an American-made two-door coupe introduced for model year 1970, and manufactured over six generations through model year 2007. It was marketed as a personal-luxury coupe through most of its history, with the last model version being classified as a full-sized coupe...
(1978–1988) - GMC CaballeroChevrolet El CaminoThe Chevrolet El Camino is a coupe utility vehicle produced by the Chevrolet division of General Motors for the 1959–1960 model years in response to the success of its rival, Ford Ranchero. Production resumed for the 1964–1977 model years based on the Chevelle platform, and continued for the...
(1978–1987) - Oldsmobile Cutlass SupremeOldsmobile Cutlass SupremeThe Oldsmobile Cutlass Supreme was a mid-size car produced by General Motors for the American market. It was always at the top of the Cutlass range. It began as a trim package, developed its own roofline, and eventually was mechanically divorced from the later, smaller Cutlasses.The Cutlass Supreme...
(1978–1988) - Oldsmobile Cutlass CalaisOldsmobile Cutlass CalaisThe Oldsmobile Calais, renamed the Cutlass Calais for 1988, and briefly available in 1987 as the limited edition GMO Quad-4, was a compact car produced by General Motors from 1985 through 1991. In part, it was intended to replace the Omega in Oldsmobile's lineup...
(1978–1984) - Oldsmobile Cutlass Cruiser (1978–1983)
- Oldsmobile Cutlass Salon (1978–1981)
- Pontiac Grand PrixPontiac Grand PrixPicking up where the Pontiac Ventura model left off, the Grand Prix first appeared in the Pontiac line for 1962. It was essentially a standard Pontiac Catalina coupe with minimal outside chrome trim and a sportier interior...
(1978–1987) - Pontiac LeMansPontiac LeMansThe Pontiac LeMans was a model name applied to compact and intermediate-sized automobiles offered by the Pontiac division of General Motors from 1962 to 1981. The LeMans was replaced by the downsized Pontiac Bonneville for the 1982 model year...
(1978–1981)