Chevrolet Corvette (C3)

The Chevrolet Corvette (C3) is a sports car that was produced from 1967 until 1982 by Chevrolet for the 1968 to 1982 model years. Engines and chassis components were mostly carried over from the previous generation, but the body and interior were new. It set new sales records with 53,807 produced for the 1979 model year. The C3 is the third generation of the Chevrolet Corvette, and marks the second time the Corvette would carry the Stingray name, though only for the 1969 - 1976 model years. This time it was a single word as opposed to Sting Ray as used for the 1963 - 1967 C2 generation. The name would then be retired until 2014 when it returned with the release of the C7.

History

Mako Shark II Concept

The Corvette C3 was patterned after the Mako Shark II designed by Larry Shinoda. Executed under Bill Mitchell's direction, the Mako II had been initiated in early 1964. Once the mid-engined format was abandoned, the Shinoda/Mitchell car was sent to Chevrolet Styling under David Holls, where Harry Haga's studio adapted it for production on the existing Stingray chassis. The resulting lower half of the car was much like the Mako II, except for the softer contours. The concept car's name was later changed to Manta Ray. The C3 also adopted the "sugar scoop" roof treatment with vertical back window from the mid-engined concept models designed by the Duntov group. It was intended from the beginning that the rear window and that portion of the roof above the seats to be removable.

The "Shark" has the distinction of being introduced to the motoring public in an unorthodox—and unintended—fashion. GM had tried their best to keep the appearance of the upcoming car a secret, but the release of Mattel's die-cast Hot Wheels line several weeks before the C3's unveiling had a certain version of particular interest to Corvette fans: the "Custom Corvette", a GM-authorized model of the 1968 Corvette.

1968–1969

For 1968, both the Corvette body and interior were completely redesigned. As before, the car was available in either coupe or convertible models, but coupe was now a notchback fitted with a near-vertical removable rear window and removable roof panels ( T-tops). A soft folding top was included with convertibles, while an auxiliary hardtop with a glass rear window was offered at additional cost. Included with coupes were hold down straps and a pair of vinyl bags to store the roof panels, and above the luggage area was a rear window stowage tray. The enduring new body's concealed headlights moved into position via a vacuum operated system rather than electrically as on the previous generation, and the new hide-away windshield wipers utilized a problematic vacuum door. The door handles were flush with the top of the doors with a separate release button. Front fenders had functional engine cooling vents. Side vent windows were eliminated from all models, replaced with "Astro Ventilation", a fresh air circulation system. In the cabin, a large round speedometer and matching tachometer were positioned in front of the driver. Auxiliary gauges were clustered above the forward end of the console and included oil pressure, water temperature, ammeter, fuel gauge, and an analog clock. A fiber-optic system appeared on the console that monitored exterior lights and there was no glove box. The battery was relocated from the engine area to one of three compartments behind the seats to improve weight distribution. New options included a rear window defroster, anti-theft alarm system, bright metal wheel covers, and an AM-FM Stereo radio.Corvette Black Book 1953-2009 All cars ordered with a radio, like the C2 cars, continued to be fitted with chrome-plated ignition shielding covering the distributor to reduce interference.

The chassis was carried over from the second generation models, retaining the fully independent suspension (with minor revisions) and the four-wheel disc brake system. The engine line-up and horsepower ratings were also carried over from the previous year as were the 3 and 4-speed manual transmissions. The new optional Turbo Hydramatic 3-speed automatic transmission ( RPO M40) replaced the two-speed Powerglide. The L30, a small-block V8 engine rated at and a 3-speed manual transmission were standard, but only a few hundred 3-speed manual equipped cars were sold. The 4-speed manual was available in M20 wide-ratio or M21 close-ratio transmission versions. The M22 “Rock Crusher”, a heavy duty, close-ratio 4-speed gearbox, was also available for certain applications. The engine line-up included the L79, a high performance version of the small-block. Also available were several variants of the big-block V8 engine, that taken together made up nearly half the cars. There was the L36, a version with a Rochester 4-barrel carburetor; The L68, a motor with a Holley triple 2-barrel carb set up (3 X 2 tri-power); The L71, generating at 5,800 rpm and at 4,000 rpm of torque also with a tri-power; The L89 option was the L71 engine but with much lighter aluminum cylinder heads rather than the standard cast iron. Then there was the L88 engine that Chevrolet designed strictly for off-road use (racing), with a published rating of , but featured a high-capacity 4-barrel carb, aluminum heads, a unique air induction system, and an ultra-high compression ratio (12.5:1). All small block cars had low-profile hoods. All big block cars had domed hoods for additional engine clearance with twin simulated vents and “427” emblems on either side of the dome. The new seven-inch wide steel wheels had F70x15 nylon bias-ply tires standard with either white or red stripe tires optional. Rare options were: L88 engine (80), J56 heavy-duty brakes (81), UA6 alarm system (388), L89 aluminum heads (624).

In 1969, small block engine displacement increased from to , though output remained the same. All other engines and transmission choices remained unchanged from the previous year, though the L30 base engine was now the ZQ3 and the L79 motor was redesignated the L46.NCRS 1968-1982 Corvette Specifications Guide All cars featured steel wheels (increased from 7 inches). Tire size remained the same, although this was the first year for optional white lettered tires and the last for red striped tires. Carried over from the previous year were seven available rear axle ratios ranging from 2.73 to 4.56. Standard ratio remained 3.08 with automatic and 3.36 with manual transmission. The optional Positraction rear axle, mandated on many engine/gearbox combinations, was installed on more than 95% of the cars. "Stingray" script nameplates appeared on front fenders, now one word, in contrast to the “Sting Ray” name used previously. Exterior door handles were redesigned so the finger plate would actuate the door, eliminating the separate release button. Backup lights were integrated into the inboard taillights, headlight washers were added, and front grilles were made all black. Side-mounted exhausts and front fender vent trim were options for this year only. On the inside, revised door panels provided additional shoulder room in the C3's tighter cabin and headrests became standard. Steering wheel diameter was reduced from 16 to 15 inches to permit easier entry and exit, the ignition switch was moved from the dash to the steering column, and map pockets were added to the dash area in front of the passenger seat. Accounting for 57% of the cars, coupes with their removable roof panels, began a trend of outselling roadsters. An extended production cycle due to a labor dispute increased '69 volume. This was the last year for the L88 engine and the only year for the ZL1 option, which offered an all-aluminum big-block engine listed at . Rare options: ZL1 aluminum block (2), J56 heavy-duty brakes (115), L88 engine (116), L89 aluminum heads (390).

Car and Driver magazine wrote in October 1968, “The small-engine Corvettes are marginally faster and extraordinarily civilized. The large-engine Corvettes are extraordinarily fast and marginally civilized.”

1970–1972

With January 1970 production, fender flares were designed into the body contours to reduce wheel-thrown debris damage. New were eggcrate grills with matching front fender side vents and larger squared front directional lamps. The previously round dual exhaust outlets were made larger and rectangular in shape. Interiors were tweaked with redesigned seats and a new deluxe interior option combined wood-grain wood accents and higher-spec carpeting with leather seat surfaces. Positraction rear axle, tinted glass, and a wide-ratio 4-speed manual transmission were now standard. The base engine (ZQ3) remained at and the L46 was again offered as a high performance upgrade. New was the LT-1, a small-block V8 engine delivering a factory rated . It was a solid lifter motor featuring a forged steel crankshaft, 4-bolt main block, 11:1 compression ratio, impact extruded pistons, high-lift camshaft