1962-77 gm B-/C-body/platform complex

1962~1964

After the wild fins era of the late 1950s, GM decided to reduce its (full) size by 1961. By 1962, when the greenhouses became less ostentatious, the full size GM models were available in five wheelbase lengths: 119” for the Chevrolet, 120” for the Pontiac Catalina, 123” for the Pontiac Star Chief/Bonneville (Pontiac wagons: 119”), also 123” for the regular Oldsmobile and Buick, 126” for the C-body Ninety-Eight and Electra, in addition to 129.5” for the regular Cadillac.

As before, the Pontiac Star Chief and Bonneville were designed to have a (4-inch) longer deck with increased trunk space, and to balance the look of the car, 3 inches were added in front of the rear wheels, preserving the rear end doors of the Catalina and its B-body compartment room (Pontiac didn’t build C-bodies). Some body styles had a deck longer than the hood.

The extra 4 inches on the Oldsmobiles and Buicks, compared to the Chevrolet, was evenly spaced behind the front wheels and ahead of the rear wheels. Despite the differences in wheelbase, interior roominess of the B-body models by body style basically was identical and partly dependent on the roof, with minor variations largely determined by the trim, while the rear doors of all B-bodies were the same width.

The 3" extra space from the C-body's in the rear compartment was also facilitated by the longer and higher roof, while the Cadillac had another 3.5” ahead of the cowl. The compartment of the four-window models gained less of that 3 inches than the six-window models, which had a longer and higher roof. The front doors of the C-body were the same dimensions as those of the B-bodies, and on Buick and Oldsmobile they were the same as those of the LeSabre and 88. The rear doors of the C-body models were therefore wider than those of the B bodies. C-bodies also had a longer deck, except for the short-deck '62 Cadillac Town Sedan and '62~'63 Park Avenue Sedan, with less luggage space than a Chevy II.

It is noteworthy that on the 1959~60 models the C-body rear doors were the same size as those of the B-body's, and on Buick and Oldsmobile they were the same as the LeSabre and 88. So the front doors on the 1959~60 C-body models were wider than the B-body's. While in 1959 and 1960 the front doors of the C-body models were wider than the rear doors, in 1961 they became the same width and from 1963 the rear doors were the widest.

All the usual body styles (2/4-door saloon, 2/4-door hardtop, 4-door wagon and 2-door convertible) were offered by the four B-body divisions, except for the 2-door sedan at Oldsmobile, for which 1961 was the last year. The B-body sedan and two-door hardtop roofs were renewed for 1962, while with the major body change for 1963 only the wagon roofs were kept. There was one example of each B-body roof style, until the arrival of the 1963 specialty 2-door hardtop roof, which was used on the Pontiac Grand Prix and Oldsmobile Starfire (and 1964 Jetstar I).

The identical 2/4-door (4-window) hardtop roofs of the C-body were renewed in 1962, while by 1963 identical 6-door 4-door sedan/hardtop roofs were new (except for the different Sixty Special 4 door hardtop roof), alongside the new (three years in a row) Cadillac 2-door hardtop roof, based largely on the B-body 4-door hardtop roof, short enough to give Cadillac the longest deck among GM full size models, with the shortest deck for the Park Avenue Sedan, for which 1963 was the final year.

1964 saw the introduction of rear fender skirts on the C-body Oldsmobile Ninety-Eight and Buick Electra, joining the Cadillac, and to set them apart from the B-body models.

After the creation of the Sedan de Ville in 1956, basically a 4-door hardtop, Cadillac didn't sell any 4-door sedans from 1957 to 1964 (except for the Seventy-Five). Cadillac called the 2-door hardtop a Coupe, a body style that was called Sport(s) Coupe in the other divisions (Holiday at Oldsmobile), 4-door hardtops were called Sport Sedan at Chevrolet, 4-door Vista at Pontiac, and Holiday Sedan at Oldsmobile, where the 6-window 4-door hardtop was called Luxury Sedan in 1963/64, and by 1964 at Buick pillarless Sedan.

GM's full-size cars of this era were mounted on an X-frame, but Pontiac and Oldsmobile replaced it from 1961 with a perimeter frame with the side beams brought out to the door sill. Oldsmobile finally replaced the rear leaf springs by coils. Canadian Pontiacs were based on the 119-inch Chevrolet X-frame, with the rear wheels one inch forward (much like American Pontiac wagons) from 1962 to 1964.

In 1959/1960 and 1963/1964 each of the rear wheels of the Canadian Pontiacs had been placed an uncomfortable 6 cm more inwards in the wheel arches than on the US ‘wide track’ Pontiacs, and each of the front wheels well over 4 cm in 1959/1960 and about 3 cm in 1963/1964.

By 1963 the styling had become less modest and sharper, but not for long.

			extra inch w/b*
		compared	center pillar to:			thin C-pillar					specialty			61-62 curved A-pillar
	w/b	to:	front	rear	2S	4S	2H	2H	4H	4H	2H	4W	Cv
Chevrolet	119		0	0	62	62	61-62	62	61-62			61-62	61-62	Biscayne, Bel Air, Impala
Chevrolet	119		0	0	63-64	63-64		63-64		63-64		63-64	63-64	Biscayne, Bel Air, Impala
Catalina '61	119	Chevrolet	0	0			61		61			61-62	61	+ Ventura
Catalina '62	120	Chevrolet	0	+1	62	62		62	62			↑	62	+ Grand Prix
Catalina	120	Chevrolet	0	+1	63-64	63-64		63-64		63-64	63-64	↑	63-64	+ Grand Prix
Pontiac wgn	119	non-wagon	0	-1								62
Pontiac wgn	119	non-wagon	0	-1								63-64		incl. Bonneville
Bonneville	123	Catalina	0	+3		62	61	62	61-62				61-62	+ Star Chief
Bonneville	123	Catalina	0	+3		63-64		63-64		63-64		↑	63-64	+ Star Chief
Pontiac CDN	119	Catalina '62	0	-1	62	62		62	62			↑	62	Strato-Chief, Laurentian, Parisienne
Pontiac CDN	119	Catalina	0	-1	63-64	63-64		63-64		63-64		63-64	63-64	Strato-Chief, Laurentian, Parisienne
Olds 88	123	Chevrolet	+2	+2		62	61	62	61-62			61-62	61-62	+ Starfire
Olds 88	123*	Chevrolet	+2	+2		63-64		63-64		63-64	63-64	63-64	63-64	+ Starfire, Jetstar I
LeSabre	123	Chevrolet	+2	+2	62	62		62	61-62			61-62	61-62	+ Invicta (Wildcat)
LeSabre	123	Chevrolet	+2	+2	63	63-64		63-64		63-64		63-64	63-64	+ Wildcat (Invicta)
* AMA: wagon 121.7							↑				↑
		* not GM-sourced				'62 Bel Air				Grand Prix
										Starfire, Jetstar I
			extra inch w/b*
		compared	center pillar to:						thin C-pillar
	w/b	to:	front	rear	4S6w	4H6w	4S6w	4H6w	2H	4H	2H	4H	2H	4H6w	4L	Cv
Ninety-Eight	126	88	0	+3	61-62	61-62			61	61	62	62				61-62
Ninety-Eight	126	88	0	+3			63-64	63-64			63-64	63-64				63-64
Electra	126	LeSabre	0	+3	61-62	61-62			61	61	62	62				61-62
Electra	126	LeSabre	0	+3			63-64	63-64			63-64	63-64				63-64
de Ville	129.5	Ninety-Eight	+4.5	-1		61-62			61	61	62	62				61-62	+ Sixty-Two, Eldorado Biarritz
de Ville	129.5	Ninety-Eight	+4.5	-1				63-64				63-64	63-64			63-64	+ Sixty-Two, Eldorado (Biarritz)
Sixty Special	129.5	de Ville	0	0										61-62
Sixty Special	129.5	de Ville	0	0										63-64
Seventy-Five	149.75	Sixty Special	0	+20.25											59-62
Seventy-Five	149.75	Sixty Special	0	+20.25											63-65

		* not GM-sourced

1965~1968

Then came the dazzling 1965 models. Preceded by the 1964 intermediates, GM's full sizers had a more integral look thanks to the curved side pillars and windows. Also, developed from the intermediates, perimeter frames were now commonly used for all full-size GM models (1966 for the Cadillac Fleetwood Seventy-Five).

Pontiac's styling was certainly the most spectacular, Oldsmobiles had a bold look with their open rear wheel arches, Chevrolets were simply attractive, while Buicks looked more reserved, but all had the rising beltline introduced by GM in 1963 with the Buick Riviera, and in 1964 on the Chevelle hardtop and started out as a character crease on the 1961 Pontiacs. As a distinctive brand, Cadillac didn't pick up on this and eventually gave up its raised fins, creating an understated yet stately look, while retaining the rear fender skirts, introduced in the late 1950s. Ironically, on the 1953 Eldorado, Cadillac had introduced used drop-down window lines, which were soon adopted by the other divisions, and by 1957 it was close to what would happen in the 1960s.

The roof sail panel of the spectacular ‘sweepline’ 2-door B-body hardtop was positioned directly over the rear wheels on the Buick and long Pontiacs, while on Chevrolet, Catalina and Oldsmobile the wheels were 3 inches 'off-balance' towards the front.

On Chevrolet and Pontiac Catalina (wheelbase lengths of 119” and 121” resp.), the hood became longer, the deck shorter, with the Pontiac Executive and Bonneville (124”) retaining the same rear doors as the Catalina, the extra inches in front of the rear wheels, as well as the longer deck.

In a surprising move, the 4 inches extra wheelbase on B-body Oldsmobiles was now allocated entirely to the hood, while on Buick it was allocated ahead of the rear wheels, largely mimicking the Electra's rear doors, without adding to ease of entry of the rear compartment as GM's B-body compartment dictated a narrower interior door opening than with the C-body. In this way Pontiac (without C-body) did not bother to widen its rear doors for the Executive and Bonneville.

So, the Buick LeSabre's greenhouse started just as far from the front wheels as the Chevrolet, with the rear wheels 4 inches backward, while the Oldsmobile's compartment/roof ended in the same place above the rear wheels as the Chevrolet, with the front wheels 4 inches. forward. Buick's B-body Wildcat also had the 3-inch longer hood of the Electra, minus the 4 portholes in a row. These layouts would last from 1965 to 1968.

So, the C-body Electra used equally wide rear doors as the B-body Buicks, with its increased roominess and different windows mainly defined by the C-body roofs, while the extra 3 inches of wheelbase were attributed to the longer hood, now justifying the extra porthole. The Wildcat had exactly the same layout (wheelbase, windshield position, door length), but less leg and headroom at the rear due to its B-body roof. As before, Electra and Ninety-Eight front doors were the same as used on the LeSabre and 88.

The Ninety-Eight had the same long hood as the B-body Oldsmobile and, as usual, had 3 inch wider rear doors. The position of the compartment between the front and rear axles was about an inch less backward than on the Electra, due to the fact that the Delta 88's compartment started at Chevrolet's position and that of the LeSabre ended there with a wheelbase difference of 4 inches between the Chevrolet (where the B-body fits exactly) versus the 3 inches between the Oldsmobile/Buick B- and C-bodies.

The rising beltline was also used on the Electra and Ninety-Eight, distinguishing them from the earlier models. Six-window models with the sixth window behind the rear doors were no longer offered (except for the extended Cadillac Fleetwood Seventy-Five), and the Ninety-Eight Luxury (a trim line) and Town Sedans became sedans with frameless windows, as did the Electra Sedan.

By 1965 Cadillac extended the wheelbase of the Fleetwood Sixty-Special to 133” with the 3.5 inches granted to the rear compartment. Thus, the 15-inch longer wheelbase compared to the Chevrolet was roughly evenly spaced behind the front wheels on one side and in front of the rear wheels on the other, as was the case with the 7 inches that distinguished the Ninety-Eight and Electra from the Chevrolet.

B-body sedan roofs were the same from 1965 to 1968, and wagon roofs until 1970. Hardtop roofs were renewed with the bi-annual body changes, including the special 2-door hardtop, while a formal 2-door hardtop roof was made for the Caprice by 1966, retained with the 1967 body change, but refreshed by 1968, when it was also offered as an Impala Custom.

C-body sedan roofs were also the same from 1965 to 1968, while the hardtop roofs were refreshed with the biannual body changes. Cadillac initially shared the 4-door hardtop roof with the other C-body divisions and also used it for the 2-door hardtop, but offered its own roofs from 1967.

Two-door sedans were now limited to Chevrolet until 1969 and Pontiac, until 1968. This forced Pontiac Canada to add Strato-Chief and Laurentian 2-door hardtops, at a higher price than the 4-door sedans.

After Buick and Oldsmobile in February 1964 released intermediate skyroof wagons on a 5-inch extended wheelbase, the 1965~69 full size wagons were limited to Chevrolet and Pontiac. The Chevrolet Caprice models (initially in February 1965 as option pack) were hardtops and called Custom Sedan and Coupe (added for 1966), Caprice Sedan and Coupe by 1968. Pontiac lost the Sport and Vista designations by 1967. The Cadillac Sedan de Ville now got a fixed center pillar, but the windows remained frameless, while the 4-door hardtop (w/o center pillar) was called the Hardtop Sedan de Ville.

It should be noted that with the 1965~1968 LeSabre rear wheel arch set 4 inches back, a possibly designed wagon would have too little room for the 3rd seat. Actually, the skyroof wagons, could be considered, although less wide, as downsized B-body wagons 12½ years in advance, with the benefit of a forward-facing rear seat (with limited room due to a well over the rear axle).

Canadian Pontiacs still were based on the 119-inch Chevrolet frame, and due to the now 121-inch wheelbase of their US equivalents, both front and rear wheels were set one inch toward each other.

The flamboyant ‘65/’66 styling was further accentuated by 1967, when Cadillac adopted the beltline rise, even for their limousines, making the 1966 limousine a one-year rarity. The Wildcat received rear fender skirts in 1967 and 1968, which became optional on the Chevrolets.

1969~1970

By 1969, all wheelbases increased by an inch, except on Chevrolet and Cadillac, resulting in a 3-inch difference between Pontiac and Chevrolet, as in 1959. The fastback roofline on the B-body 2-door hardtops, after four years, was ‘out’ and replaced by a more formal roof. Major changes to the body layout occurred on Buick, which now shared the same layout as Oldsmobile, with narrower rear doors, and granting the now 4 extra inches to the hood (now as long as that of the Electra, despite one less porthole), and the C-body's 3 inches in front of the rear wheels. The Wildcat became a rebadged LeSabre, as it did at its start in 1962.

The dimensions of the front and rear doors were again approximately the same on the C-body models, as in 1961. The wagon roof was the only roof that was not renewed.

By 1970, Buick discontinued its skyroof wagons and introduced the B-body Estate Wagon, taking advantage of the revised body/platform positioning. Sales were considerably higher than those of the skyroof Sportwagon.

The rise in beltline now was less rounded, more stylized, and only rudimentary at the end of the rear doors of the 4-door models. You could say it now had a more convex than concave appearance which was especially welcome on the luxury C-body models.

The Canadian Pontiacs' wheelbase was now 3 inches less than that of the US Pontiacs, prompting GM Canada to move the front wheel wells 2 inches backward, with the usual 1 inch forward placing of the rear wheels within their wells, rather than shortening the entire front end as was done at the 3 inches difference in 1959 and 1960. Placed on the Chevrolet chassis, each of the wheels was also further moved inward about a quarter of an inch.

Using the Chevrolet wagon chassis for all of its models, the front track on the 1968 Canadian Pontiac became a half inch wider than in the US, but this reversed the next year, when the Americans added an inch, making it as wide as the rear track.

										Grand Prix
			extra inch w/b*							Grande Parisienne				Caprice	Caprice +
		compared	center pillar to:							Starfire, Jetstar I					Impala Custom
	w/b	to:	front	rear	2S	4S	2H	2H	4H	4H	2H	4W	Cv	2H	2H	2H	2S	4S	2H	4H
Chevrolet	119		0	0	65-66	65-66	65-66		65-66			65-66	65-66	66							Biscayne, Bel Air, Impala (Super Sport), Caprice
Chevrolet	119		0	0	67-68	67-68		67-68		67-68		67-68	67-68	67	68						Biscayne, Bel Air, Impala (SS), Caprice
Chevrolet	119		0	0								69-70	69-70			69-70	69	69-70	69-70	69-70	Biscayne, Bel Air, Impala, Caprice, Brookwood, Townsman, Kingswood (Estate)
																w/b
Catalina	121	Chevrolet	+2	0	65-66	65-66	65-66		65-66		65-66	65-66	65-66	Catalina		121					+ Grand Prix (+ 2+2)
Catalina	121	Chevrolet	+2	0	67-68	67-68		67-68		67-68	67-68	67-68	67-68	Catalina		121					+ Grand Prix (+ 2+2, Ventura)
Catalina	122	Chevrolet	+2	+1								69-70	69-70	Catalina		122		69-70	69-70	69-70	+ Grand Prix (+ Ventura)
Bonneville	124	Catalina	0	+3		65-66	65-66		65-66			↑	65-66	Bonneville		124					+ Star Chief (Executive)
Bonneville	124	Catalina	0	+3		67-68		67-68		67-68		↑	67-68	Bonneville		124					+ Executive
Bonneville	125	Catalina	0	+3								↑	69-70	Bonneville		125		69-70	69-70	69-70	+ Executive
Pontiac CDN	119	Catalina	-1	-1	65-66	65-66	65-66		65-66		66	65-66	65-66	Pontiac CDN		119					Strato-Chief, Laurentian, (Grande) Parisienne (Custom Sport)
Pontiac CDN	119	Catalina	-1	-1	67-68	67-68		67-68		67-68	67	67-68	67-68	Pontiac CDN		119					Strato-Chief, Laurentian, (Grande) Parisienne (2+2)
Pontiac CDN	119	Catalina	-2	-1								69-70	69-70	Pontiac CDN		119		69-70	69-70	69-70	Strato-Chief, Laurentian, (Grande) Parisienne, 2+2, Safari
Olds 88	123	Chevrolet	+4	0		65-66	65-66		65-66		65-66		65-66	Olds 88		123					+ Starfire, Jetstar I
Olds 88	123	Chevrolet	+4	0		67-68		67-68		67-68			67-68	Olds 88		123
Olds 88	124	Chevrolet	+4	+1									69-70	Olds 88		124		69-70	69-70	69-70
LeSabre	123	Chevrolet	0	+4		65-66	65-66		65-66				65-66	LeSabre		123
LeSabre	123	Chevrolet	0	+4		67-68		67-68		67-68			67-68	LeSabre		123
LeSabre	124	Chevrolet	+4	+1								70	69-70	LeSabre		124		69-70	69-70	69-70	incl. Wildcat, + Estate Wagon
Wildcat	126	LeSabre	+3	0		65-66	65-66		65-66				65-66
Wildcat	126	LeSabre	+3	0		67-68		67-68		67-68			67-68
LeSabre '69	123.2	Chevrolet	+4	+0.2
					2S	4S	2H	2H	4H	4H	2H	4W	Cv				2S	4S	2H	4H

			extra inch w/b*
		compared	center pillar to:
	w/b	to:	front	rear	4S	4S	2H	2H	4H	2H	4H	2H	4H	2H	4H	2H	4H	Cv	4S	4S	4L(6w)
Ninety-Eight	126	88	0	+3	65-66		65-66		65-66									65-66
Ninety-Eight	126	88	0	+3	67-68					67-68	67-68							67-68
Ninety-Eight	127	88	0	+3		69-70								69-70	69-70			69-70
Electra	126	LeSabre	+3	0	65-66		65-66		65-66									65-66
Electra	126	LeSabre	+3	0	67-68					67-68	67-68							67-68
Electra	126.2/127	LeSabre	0	+3		69-70								69-70	69-70			69-70
de Ville	129.5	Ninety-Eight	+2.5	+1	65-66			65-66	65-66									65-66				+ Calais, Fleetwood Eldorado
de Ville	129.5	Ninety-Eight	+2.5	+1	67-68							67-68	67-68					67-68				+ Calais
de Ville	129.5	Ninety-Eight	+2.5	0		69-70										69-70	69-70	69-70				+ Calais
																w/b
Sixty Special	133	de Ville	0	+3.5										Sixty Special		133			65-66			+ Fleetwood Brougham
Sixty Special	133	de Ville	0	+3.5										Sixty Special		133			67-68			+ Fleetwood Brougham
Sixty Special	133	de Ville	0	+3.5										Sixty Special		133				69-70		+ Fleetwood Brougham
Seventy-Five	149.75	Sixty Special	0	+16.75										Seventy-Five		149.75					66
Seventy-Five	149.75	Sixty Special	0	+16.75										Seventy-Five		149.75					67-68
Seventy-Five	149.75	Sixty Special	0	+16.75										Seventy-Five		149.75					69-70

		* not GM-sourced

1971~1976

The full-size GM line reached its ultimate dimensions in the 1971-1976 period, before the downsizing of 1977. GM emphasized the long hood, short deck look, and added 2.5 inches ahead of the cowl of the Chevrolet. The winners were the Pontiac Bonneville and Grand Ville (even beating the Electra and Ninety-Eight in overall vehicle length in the first year) which had an extra 2.5 inches of space between the front wheels and the cowl over the Catalina, which itself had 2 inches more hood space than the Chevrolet. But after two years, Pontiac wisely chose to bring its wheelbase in line with that of the regular Buick and Oldsmobile, which had a 2.5-inch longer hood than the Chevrolet. The 1973 Grand Ville got rear fender skirts as a sort of compensation, adopted for 1975 by the Bonneville, which previously had them from 1965 to 1970, when they were optional on other full size Pontiacs.

The front doors were now wider than ever, and those of the C-bodies were wider than the rear doors and matched those of the B-bodies. All of the C-body rear doors, which were 3 inches wider than the B-body rear doors, were the same width, including those on the Cadillac de Ville with a longer rear compartment, and the even longer Fleetwood Brougham with its 3-inch middle pillar.

On the B-bodies, the rise in beltline was gone at the 2-door hardtop models, except on Chevrolet, while Pontiac returned to the characterline rise that started it all 10 years earlier, resulting in one of the most attractive offerings among the divisions. With a low-key sweep line, Buicks looked perhaps even better. The rear fender skirts on the Chevrolet Caprice were now standard equipment, Chevrolet added a ‘beltline-rise-free’ coupe by 1974, and, after 10 years, from autumn 1974, GM’s sedans got a more even greenhouse bottom line.

Opera windows came by 1974 on the 2-door hardtop, transforming the Chevrolet into a coupe and also on the other marques, that kept the hardtop roll-down rear quarter window, and for 1975 on the 4-door hardtop models. Conventional 2-door hardtop models remained available only on Chevrolet until 1975. By 1976 Oldsmobile offered an optional opera roof, turning the 2-door hardtop into a coupe.

For 1975 the sedans got an extra window in the rear doors to allow the glass to slide down, as the roof sail panel became narrower due to an increased glass area.

Sedans and convertibles were now denied to C-bodies (with the exception of the Cadillac Fleetwood Brougham sedan).

The rising beltline returned at the rear doors of the 4-door Oldsmobile Ninety-Eight and Buick Electra until 1975, when they disappeared at the 2-doors, with the addition of the opera windows in the roof sail panel, which began on the 2-door Cadillac with an upright B-pillar for 1974. At the same time, with the slightly backward sloping B-pillar of the 1971~74 hardtop body, Buick created the Landau option on the Electra with opera window by means of a multiform opening in the roof padding, later followed by Oldsmobile with a simple elongated opening on the Ninety-Eight Elegance, both with the rising beltline below.

While the 2-door hardtop 1971-72 Centurion was called Formal Coupe, due to its smaller back window, the 1971~76 2-door hardtop LeSabres and 2-door Electras were called Hardtop Coupe, regardless of roof edition. The 1971 Oldsmobile Delta 88 Royale with the same roof as the Centurion, was called Hardtop Coupe, as were the 1971~76 Delta 88 and 1971 Ninety-Eight 2-door hardtops, while the 1972~76 2-door Ninety-Eights were named Coupe, with Oldsmobile hardtops losing the Holiday designation.

All 1971~76 2-door hardtop Pontiac full size models were called Hardtop Coupe, while Chevrolet called the 2-door hardtop Impala a Sport Coupe, except for the Custom Coupe models which shared the roof with the Caprice Coupe.

At Cadillac, the Sedan de Ville was a 4-door hardtop again, as it was before 1965. The Caprice Sedan became a 4-door sedan by 1972, with the 4-door hardtop called Sport Sedan.

The third rear-facing seat in the wagons was now forward instead of backward. The Oldsmobile Custom Cruiser had rear fender skirts, making it look like a Cadillac wagon.

B-body roofs:

opera window:

curved

obtuse

curved

obtuse

triangular

trapezoid

triangular

trapezoid

Chevrolet Impala:

Sport Coupe

Custom Coupe

extra inch* w/b

CDN + Bel Air

+ Caprice Coupe

center pillar to:

w/b

compared to:

front

rear

4H6w

Wgn

Chevrolet

121.5

71-74

75-76

71-73

74-75

71-73

74-76

71-74

75-76

71-75

Biscayne, Bel Air, Impala, Caprice

Chevrolet wagon

125

non-wagon

+3.5

71-76

Brookwood, Townsman, Kingswood (Estate)

* Catalina

123.5

Chevrolet

71-74

75-76

71-73

74-76

71-74

71-72

+ (CDN) Laurentian, Parisienne

Pontiac wagon

127

non-wagon

+3.5

71-76

(Grand) Safari

Bonneville

126

Catalina

+2.5

71-72

Bonneville

124/123.4, rebadged Catalina

73-74

75-76

C-body roofs ↙

Grand Ville

126

Catalina

+2.5

71-72

C-body roofs ↙

Grand Ville

124/123.4, rebadged Catalina

73-75

C-body roofs ↙

Delta 88

124

Chevrolet

+0.5

71-74

75-76

71-73

74-76

71-74

75-76

71-75

Oldsmobile wagon

127

non-wagon

71-76

Custom Cruiser

* LeSabre

124

Chevrolet

+0.5

71-74

75-76

71-73

74-76

71-74

75-76

71-75

+ Centurion

Buick wagon

127

non-wagon

71-76

Estate Wagon

* notes:

Catalina 73-74

124

Chevrolet

+0.5

Catalina 75-76

123.4

Chevrolet

-0.1

LeSabre 74-75 CDN:

123.5

Chevrolet

4H6w

Wgn

↑

* not GM-sourced

'71 Delta 88 Royale

'76 Delta 88 Royale

71-72 Centurion

Crown Landau

C-body roofs:

opera window:

right

obtuse

trapezoid

extra inch* w/b

center pillar to:

w/b

compared to:

front

rear

4H6w

4L(6w)

Bonneville

123.4

75-76

Grand Ville

126

Catalina

+2.5

71-72

Grand Ville

124/123.4

73-74

Ninety-Eight

127

Delta 88

71-74

74½

75-76

71-74

75-76

Electra

127

LeSabre

71-74

75-76

71-74

75-76

de Ville

130

Ninety-Eight

71-73

74-76

71-74

75-76

+ Calais

Fleetwood Brougham

133

de Ville

71-76

Seventy-Five

151.5

Fleetwood Brougham

+18.5

71-76

↑

* not GM-sourced

'74½ Ninety-Eight Elegance option:

with small oblong opera window

'74 Electra Landau option:

right trapezoid with baseline rise

w/b	Chevrolet	Chev. wgn	Catalina	Bonneville	Pont. wgn	Parisienne	Delta 88	Olds wgn	Ninety-Eight	LeSabre	Wildcat	Buick wgn	Electra	de Ville	Sixty Special	Seventy-Five	w/b
119	1961~1970	1961~1970	1961		1961~1964	1961~1970											119
120			1962~1964														120
121			1965~1968		1965~1968												121
121.5	1971~1976																121.5
122			1969~1970		1969~1970												122
123				1961~1964			1961~1968	1961~1964		1961~1968		1961~1964					123
123.2										1969	←						123.2
123.4			1975~1976	←													123.4
123.5			1971~1972			1971~1972											123.5
124				1965~1968													124
124			1973~1974	←		1973~1976	1969~1976			1970~1976	← (1970)	1970					124
125		1971~1976		1969~1970													125
126				1971~1972					1961~1968		1965~1968		1961~1968				126
126.2													1969				126.2
127					1971~1976			1971~1976	1969~1976			1971~1976	1970~1976				127
129.5														1961~1970			129.5
130														1971~1976			130
133															1965~1976		133
149.75																1961~1970	149.75
151.5																1971~1976	151.5

1962

1963

1964

1965

1966

1967

1968

1969

1970

1971

1972

1973

1974

1975

1976

1977

CPB

Chevrolet

CPOBNE

CPOBNEV

CPOBNE

CPOB

CPOBNEV

Pontiac

CPOBNEV

CPOBNE

CPOB

POB

Oldsmobile

CNEV

CPNEV

CPONEV

CPOBNEV

Buick

CPOBNEV

Ninety-Eight

CPOB

CPB

CPOB

Electra

CPOBNEV

CPOB

de Ville

1977

The downsizing of regular GM cars was the industry's first. With the wheelbase reduced to intermediate level, there was no more room for sliding the greenhouses, but the compartment space remained level. The habit of adding seemingly useless sheet metal between the front wheels and the cowl, to discern the other divisions from the Chevrolet, while using similar greenhouses that defined interior space eventually came to an end. The Buick and Oldsmobile C-bodies got a longer compartment and a longer wheelbase, which was still under the 119" common to the Chevrolet in the 1960s, and yes, to match its 7-liter engine and amenities, Cadillac was allowed to add 2.5 inches of prestigious metal for the hood and wheelbase, equaling Chevrolet’s wheelbase of the previous generation. The Sedan de Ville now was a sedan again. Incidentally, the 1977~1979 Chevrolet and the Canadian Pontiac were the only ones with a long in-line 6-cylinder (as happened until 1973).

Body styles were limited to 2-door coupe, 4-door sedan, one each for B-bodies and C-bodies, and wagon, the latter returning to the rear-facing third seat. Unification of body panels increased, with doors shared between Chevrolet and Pontiac, and between Buick and Oldsmobile, while all wagon main body panels equaled the Chevrolet except for the front wings.

New sheet metal arrived in 1980, and all wagons now matched the Chevrolet in the body panels, rather than each using their own front wheel opening. In addition to the LeSabre wagon, a B-body Electra wagon was made. When the Pontiac was scrapped in the United States in 1982, it became a rebadged Chevrolet in Canada, also to be sold down the border the following year, but finally deleted in 1986. The rear-wheel-drive C-body ended in 1984, when the Cadillac (Fleetwood) Brougham became a D-body, lasting until 1992. Except for wagons, B-body Buick and Oldsmobile ended in 1985, Chevrolets of this generation in 1990.

Summary

Despite the large number of wheelbases, and apart from the D-body limousine, there are only two GM ‘full size’ interior compartment volumes (depending on body style): B-body and C-body.

In order to achieve the difference between B-body and C-body, the cost-effective method of extending the front doors and roof above was adopted in 1959 and 1960, reducing the number of roof ends/rear windows to just four (2/4-door sedans, 2-door hardtop, 4-door hardtop and wagon), in addition to two windshields, one for the sedans/wagon, the other, lower for the hardtops/convertible. From 1961 the rear doors of the C-body were the widest, and the number of roof ends doubled, increasing to ten by 1966.

Originally, the ‘59 models were to have been facelifted ‘58s, but when GM’s design staff took a look at Chrysler's new '57 “forward look” cars (designer Virgil Exner was formerly of GM) in the late summer of 1956, new style boss Bill Mitchell instituted a crash program to redesign all the ‘59s. Because of the limited time frame, many 1959 GM cars had to share lots of components, much more so than was historically normal.

In the period 1959~1970, Chevrolet's 119-inch wheelbase determined the minimum size of the B-body compartment. Pontiac Catalina surpassed the Chevrolet wheelbase by one inch in 1962, then 2 inches, and 3 inches in 1969 and 1970, just like 10 years earlier. Pontiac's Star Chief/Executive & Bonneville, with the rear doors of the Catalina, had the wheelbase extended by 3 inches in front of the rear wheels to balance the look of the car with its 4 inch longer deck (3 inches by 1969). The extension for the B-body Oldsmobile and Buick was 4 inches and 5 inches in 1969 and 1970, with the 1965-1968 Buick Wildcat an extra 3 inches before the coil.

C-body Oldsmobile Ninety-Eight and Buick Electra wheelbase was consistently 3 inches over their B-body 88 and LeSabre models, with regular Cadillacs getting an extra 3.5 inches, mostly assigned to the hood, while the 1965~70 Sixty Special received another 3.5 inches in front of the rear wheels, allotted to the rear compartment.

When Chevrolet's wheelbase grew to 121.5" in 1971, the GM B-body stablemates were given a 2-inch longer hood and there was no additional room to vary the position of the B compartment. C-body Oldsmobile Ninety-Eight and Buick Electra wheelbase was consistently 3 inches longer as usual. This time GM wisely chose to add the 3 inches extra wheelbase length from the regular Cadillac to the rear compartment, and add a second 3 inches to that of the Fleetwood Sixty Special. Pontiac however, added the 2.5 inch longer sheet metal of its 1971-72 Bonneville/Grand Ville to the hood.

The B-body sedan/wagon windshield was now shared with the C-body 2-door hardtop, while the C-body 4-door hardtop had its own taller windshield. Grand Ville and 1975/76 Bonneville 2-door hardtop/coupe had C-body roofs, increasing rear leg room by 3 inches, and equaling that of the 4-door Pontiacs.

At the downsizing of 1977, all B-body models had the same 115.9-inch wheelbase, while those of the C-body Buick and Oldsmobile had 118.9 inches, attributed of course to the rear compartment, with Cadillac’s wheelbase extending to 121.5 inches thanks to a longer hood. The 1977 Ninety-Eight and Electra became the first rwd models whose wheelbase was the minimum size for the C body compartment, and after the 1980 facelift would last until 1984.

So where previously B-body customers were given a choice of four lengths between the front and rear wheels to get around, C-body buyers were again offered a choice of two lengths: Cadillac or non-Cadillac, after two Cadillac lengths were offered from 1965 to 1976.

		1962	1963	1964	1965	1966	1967	1968	1969	1970	1971	1972	1973	1977
B-body	Chevrolet	119	119	119	119	119	119	119	119	119	121.5	121.5	121.5	115.9
	Chevrolet wagon	119	119	119	119	119	119	119	119	119	125	125	125	115.9
	Pontiac	120	120	120	121	121	121	121	122	122	123.5	123.5	124	115.9
	Bonneville	123	123	123	124	124	124	124	125	125	126	126	124	115.9
	Pontiac wagon	119	119	119	121	121	121	121	122	122	127	127	127	115.9
	Oldsmobile	123	123	123	123	123	123	123	124	124	124	124	124	115.9
	Oldsmobile wagon	123	123	123							127	127	127	115.9
	Buick	123	123	123	123	123	123	123	123.2	124	124	124	124	115.9
	Buick wagon	123	123	123						124	127	127	127	115.9
	Wildcat		123	123	126	126	126	126	123.2	124
C-body	Ninety-Eight	126	126	126	126	126	126	126	127	127	127	127	127	118.9
	Electra	126	126	126	126	126	126	126	126.2	127	127	127	127	118.9
	de Ville	129.5	129.5	129.5	129.5	129.5	129.5	129.5	129.5	129.5	130	130	130	121.5
	2-door hardtop		129.5	129.5
	Town Sedan/Park Avenue	129.5	129.5
	Sixty Special/Fleetwood Brougham	129.5	129.5	129.5	133	133	133	133	133	133	133	133	133	121.5

long hood
xlong hood
long deck
short deck

Sources: wildaboutcarsonline https://www.xr793.com/

American Cars 1962-1977