The Classic 1968 Corvette Specs

“Corvette ’68… all different all over”. 1968 was a year of bold new design changes for the Corvette. The ’68 vette underwent a complete body redesign, shifting towards that almost convertible feel with removable T-tops and a removable back window.

Go hardtop

In 15 years of Corvettes, the car had not only driven into prominence in the sports car field, but had also been a forerunner of some exciting and practical automobile innovation. For 1968, the mechanics of the Stingray were improved and refined; this year was an inspiring year in terms of design. This Corvette boasted uncommon, removable sections over pilot and navigator, that lift out for open air moving. A nearly vertical glass rear window tucks out of the way into a compartment in the luggage area. The effect is a flow-through roof that had never been seen on an American sports car before. Long, low profile with blunt styling brings up the rear per the continental GT tradition. The aerodynamic design features a spoiler in the back. Behind front wheels, functional louvers help to keep the horses cool. Wraparound front and rear bumpers plus line-smoothing hideaway features help make Corvette a trim one style-side. On the nose end, vacuum operated headlights glide open automatically when lights are turned on. Windshield wipers are hidden under a power operated panel which activates when the wipers are turned on or off, so that they aren’t around when they shouldn’t be. Below belt-line, wheel trim rings and center caps cover big 7-inch-wide wheels. Special tuck in treatment goes to the bright metal body sill between the wheels. Front and rear marker lights add a special touch to the Corvette from the sidelines.

Uncap it

The Corvette Convertible takes the same basic stingray idea with the lid off and turns in top-down driving for two. Drivers of the ’68 Corvettes had three options of how to put the top on. Soft top (in black, white, or beige) or removable hardtop- pick either one as standard or order them both together. There is a big story in glass for the ’68 Corvette Convertible. Like the Coupe, and like all previous Corvettes since ’53, a rustless fiber glass body is basic. Full door glass styling aids in visibility as well as appearance and the Convertible’s removable hardtop has a glass rear window for the first time. Both the Coupe and Corvette Convertible start off with a 300-hp Turbo-Fire 327 V8 standard along with a fully synchronized 3-speed box. Four other engines are available, and with 427 V8’s there is a special high-domed hood. Additional transmission choices are 4-speed, close ratio 4 speed and Turbo Hydra-Matic- which broke into the Corvette power team lineup in 1968. For comfort, air flows through Corvette with full door windows closed, thanks to the new Astro Ventilation system with vent ports in the driver and passenger sides of the instrument panel.

Settle Down

The 1968 Corvette cockpit is designed with the traveling duo in mind. Thin tapered and contoured buckets are very comfortably high-backed. Supple all-vinyl upholstery is standard, and there was an option to order genuine leather. Between the seats the center console houses the parking brake lever, gear shift, cigarette lighter and ashtray, thumb-wheel heater controls, air vent controls, and light monitoring system indicators. The console also stows seat belt buckle straps- twin sets with push button buckles. The option to order AM/ FM radio was available with or without FM Stereo multiplex. New features like the seat belt reminder light and door ajar flashers were introduced. A new ignition alarm system to remind you to take the key when you leave the car was also introduced.

Take Control

The mechanical part of Frame, chassis and power team members give the enthusiast precise handling of a smooth-but-hustling road car.
Body- A network of steel integrated with body panels for increased rigidity and strength. The fiber glass body parts are bonded directly to the steel frame rather than to riveted bonding strips as in the past. Both the Sting Ray Coupe and Convertible bodies are given extra strength through increased supports and support reinforcements.
Frame- All-welded, full-length, ladder-constructed with five crossmembers. Side rails and intermediate crossmembers box section; front crossmember box girder section. Eight body mounting points plus two radiator mounts.
Suspension- In front, independent type with coil springs and concentric shock absorbers. Spherically jointed steering knuckles for each wheel. Reinforced stamped steel control arms with pre-loaded steel-encased rubber bushings at pivots. Double-acting hydraulic shock absorbers with 1″ piston diameter. Link-type stabilizer bar of steel with rubber bushings. Anti-dive control is achieved through the angle of front upper control arm. Rear suspension is fully independent with frame-anchored differential. Locus of each wheel is established by three links: universal jointed axle shaft, adjacent strut, and a torque control arm pivoted at frame side rail. Vertical suspension loads taken by shock absorbers and transversely positioned nine-leaf spring.
Rear Axle- Semi-floating straddle mounted hypoid gear with 3.7 pint capacity. MPH is final drive with various rear axle ratios per 1000 rpm; 2.73-28.6; 3.08-25.4; 3.36-23.3; 3.55-22.0; 3.70-21.1; and 4.11-19.0 (these are calculated for new F70-15 wide oval tires without allowance for tire slippage or expansion).
Steering- Semi-reversible, recirculating ball-nut steering gear with GM-developed energy absorbing column. Steering damper between frame and relay rod mounted on the tie rod. Dual-mounted steering arm tie rod connection permits a choice between street or fast ratio. Turning diameter curb to curb- 39.9 ft. Number of turns lock to lock with street steering- 3.4 fast- 2.92, Power steering is a pump-powered hydraulic cylinder assisting the parallelogram linkage. Number of turns lock to lock with power-steering- 2.92.
Brakes- First American production car to use disc brakes at all four wheels. Dual circuit master cylinder with warning light. Braking effort is distributed 65% to front and 35% to rear. Construction is cast iron caliper type with radial cavities for heat dissipation. Sweep area is 461.2 square inches. Linings are woven asbestos; gross lining area is 81.7 square inches. Parking brake is mechanically operated on rear wheels separate from service brake system. Drum diameter of parking brake is 6.5″. Linings consist of two shoes per rear wheel with gross lining area of 33.9 square inches. Power brakes with new tandem diaphragm vacuum unit could be specified to lessen the required amount of pedal pressure.
Engines- All corvette engines used cast iron alloy cylinder blocks. Full-lengthwater jackets surround each cylinder for optimum cooling. Cylinder heads are high chrome cast iron alloy. Total combustion chamber volumes, piston top center, are: 300-hp-4.69-cu-in; 350-hp-4.17-cu-in; 390- and 400-hp- 5.90- cu- in; and 435-hp-4.92-cu.-in. Inlet manifold on 300- and 350-hp engines is of cast iron alloy. With 390- 400- and 435-hp, inlet manifold is of cast aluminum alloy. Exhaust manifolds on all engines are cast iron alloy. The 327 engines utilize dual 4-port exhaust flow to a single outlet runner at the center; 427s use dual 4-port extended runners from each port converging to a rear outlet. Rugged alloy steel crankshaft with five main bearings in all engines. Crank arm length: 327-1.625;427-1.8. There are 6 counterweights on all cranks. Rubber mounted inertia torsional damper. Steel sprocket and chain timing gear. Camshaft in all engines is cast iron alloy with 5 steel-backed Babbitt bearings. Valve train in each engine includes stamped individually mounted overhead rocker arms. Push rods actuated with hydraulic lifters (except the 435-hp which has solid lifters). Intake valves are steel alloy. Overall head diameter of intake valves in 300-hp engine is 1.935-1.945; 350-hp-2.017-2.023; 390 and 400-hp mills- 2.060-2.070 and 2.185-2.195 in the 435-hp. Exhaust valves are of steel alloy. Head diameters: 300-hp-1.495 -1.505; 350-hp – 1.595-1.605 and 1.715-1.725 in all the 427 engines. Rochester 4-barrel downdraft carburetors are used in the 300-,350- and 390-hp engines while the 400- and 435-hp power plants utilize a Holley triple 2-barrel downdraft system. All Corvette engines in ’68 feature Air Injection Reactor equipment to control exhaust emission.
Transmissions- The standard 3-Speed transmission available only with the 300-hp engine has these gear ratios: first- 2.54:1; second- 1.50:1; third 1.00:1 and reverse- 2.63:1. 4-Speed ratios are: first- 2.52:1; second- 1.88:1; third- 1.47:1; fourth- 1.00:1; reverse-2.59:1. The special 4-Speed close-ratio transmission goes: first- 2.20:1; second- 1.64:1; third- 1.27:1; fourth-1.00: 1; and reverse- 2.26:1. All forward gears in manual transmissions are fully synchronized. A single dry disc centrifugal clutch is used with all manual transmissions. Turbo Hydra-Matic gear ratios: first- 2.48:1; second-1.48:1; third-1.00:1; and reverse-2.08:1.
Dimensions- Wheelbase-98.0″. Width overall-69.2″. Length overall- 182.1″. Tread-front: 58.3″; rear: 59.0″. Height (loaded) overall- Coupe: 47.8″; Convertible: 47.9″. Curb weight- Coupe: 3210; Convertible, 3220.
Fuel Tank: For the first time in Corvette, a 20-gallon plastic fuel tank. Weighs less than conventional tank and eliminates chances of rust and corrosion.

Engine Specifications

Feature	Base RPO L75	RPO L79	RPO L36	RPO L71	RPO L88
Type	V-8, Overhead valve
Block	Cast iron block
Displacement	327 cid	427 cid
Bore & Stroke	4.00 x 3.25″	4.251 x 3.76″
Compression ratio	10.25:1	11.0:1	10.25:1	11.0:1	12.5:1
Brake horsepower	300 @ 5000	350 @ 5800	390 @ 5400	435 @ 5800	560 @ 6400
Torque	360 lb-ft @ 3400	360 lb-ft @ 3600	460 lb-ft @ 3600	460 lb-ft @ 4000
Main bearing	Five
Valve lifters	Hydraulic	Mechanical valve lifters
Camshaft		High-performance camshaft	Special-performance camshaft	Special ultra-high-performance camshaft with .5365-inch intakes
Fuel supply	Rochester Type 4MV four-barrel Model 7028207	Holley four-barrel	Three Holley two-barrels	Single Holley 850CFM four-barrel

Colors:

Tuxedo Black
Polar White
Rally Red
Lemans Blue
International Blue
British Green
Safari Yellow
Silverstone Silver
Cordovan Maroon
Corvette Bronze

Interior colorS:

Black
Red
Blue
Medium Blue
Orange
Tobacco
Gunmetal

Production Options and Build Statistics

Total 1968 Corvettes Built – 28,566
Convertibles – 18,630
Coupes – 9,936

Mechanical Dimensions

Feature	Convertible	Coupe
Wheelbase	98 inches (2.489 m)	98 inches (2.489 m)
Overall length	182.1 inches (4.625 m)	182.1 inches (4.625 m)
Overall width	69.2 inches (1.758 m)	69.2 inches (1.758 m)
Overall height		48.6 inches (1.234 m)
Front tread	58.3 inches (1.481 m)	58.3 inches (1.481 m)
Rear tread	59.0 inches (1.499 m)	59.0 inches (1.499 m)
Frame	Full-length ladder type with five cross members. Steel box sections, welded.
Front suspension	Independent, unequal-length A-arms, coil springs; tubular shocks and stabilizer bar
Rear suspension	Independent, trailing arms, toe links, transverse chromium-carbon steel leaf spring, tube shocks, and anti-roll bar
Steering	Saginaw recirculating ball, 17.6:1 ratio, 2.9 turns to lock, 39.9 turning circle
Rear axle type	Sprung differential, Hypoid gear
Brakes	Hydraulic, vented four wheel discs; 11.8-inch diameter, single calipers
Total swept area	259 sq. in. per ton, 461.2 sq. in. total
Wheels	6″ wide slotted steel 15″ 5-lug disc
Standard rear axle ratio	3.36:1
Optional rear axle ratio	3.08:1, 3.36:1, 3.55:1, 3.70:1, 4.11:1, 4.56:1