1975 Corvette Specs

“Here’s this year’s version of last year’s Best All-Around Car” boasts the 1975 Corvette sales brochure. The 1975 Corvette underwent only minor changes from the previous year’s model, keeping the best features of its predecessors and improving in other areas. The 1975 C3 marked the last model year that a true convertible Corvette was available for purchase until 1986.

The corvette body

Reinforced fiberglass shape fashioned over a steel substructure (including side-guard beams in the doors), the Corvette body is a vision. Why fiberglass? Because fiberglass gave Corvette designers the freedom to shape the body as they had to in order to create that striking, one-of-a-kind Corvette look. More than just aesthetics went into the Corvette’s build, however. The Corvette body also had to satisfy the strict demands of wind tunnel testing and development to provide the low level of aerodynamic drag that a car of this capability must have. That is why you see smooth, flowing contours, headlight doors that fold flush, flush door handles, a front air spoiler, even wipers tucked down out of the slip-stream.

In addition, fiberglass is strong, has excellent sound-deadening qualities, can’t rust or corrode. So, in Corvette you have more than just about shape. You can have one that’s efficient and practical too.

The ’75 Corvette features a new bumper system. At the rear, two frame-mounted hydraulic cylinders support an aluminum bumper that cushions minor impact and then returns to position. It’s all enclosed in an attractive, one-piece, body-color urethane cover. At the front, the attractive nose section is actually the bumper, with minor impact cushioned by a resilient honeycomb substructure (also self-restoring). One not-so-obvious advantage of the bumper system: It helps give your Corvette a chance to defend itself when it’s left alone. There’s also an anti-theft alarm that’s easily set or deactivated with a key lock in the left front fender. Additionally, the ’75 Corvette has an outside rear view mirror that is an inch wider than the 1974’s.

Corvette Coupe or Corvette Convertible? What is your preference? Of course, the coupe, along with those gorgeous lines, offers exclusive removable-and-store panels. One minute you have a clean-lined hardtop, the next, you can be opened up to the environment with the feeling of the convertible. On the other hand, the convertible features a fast-folding top that completely hides away under a flush rear deck panel. You can select a black or white top with the convertible. You can also order a removable auxiliary hardtop in body color, or with a formal black vinyl cover. What about the available body items for your Corvette? Got that covered too. A luggage carrier serves as a handsome addition to your Corvette rear deck, and a very functional one too, when you’re taking along more than your Corvette interior can handle.

 

Corvette Interior 

We know the exterior of the Corvette is pretty exciting, but the Corvette interior is nothing to overlook either. Try one on and see for yourself! The 1975 Corvette offered two options in terms of interior, the standard interior option or the custom leather trim interior. For the standard interior, lavish, textured-vinyl panels and accents on doors, dash and console are all present. Built-in armrests, an assist grip, rich color-keyed, deep-twist carpeting underfoot, sound deadeners and insulation in areas such as door panels to help make your Corvette quiet and comfortable. As for the seats; tall, command-styled, individually adjustable buckets, deep-pleated and saddle-stitched for that Corvette feeling. They’re body-contoured with deep foam for your personal comfort and added support on long trips. Directly behind the seats, you find a lockable compartment for your valuables, plus a second lighted compartment for your not-so-valuables. In addition, you have six-and-a-half cubic feet of lighted and fully carpeted luggage space. Available colors for standard interior included: Black, Dark Blue, Light Neutral, Medium Saddle, Dark Red, and Silver. Also available, custom leather trim interior, for those who want the added flair, texture, and scent of genuine leather in the seating areas, plus cut-pile nylon carpeting and custom wood-grain vinyl accents on the doors and the console. Custom leather trim interior is available in: Black, Medium Saddle, or Silver, Dark Red, or Dark Blue.

Instrument & Controls- Drivers will note that the hand brake, controls for the heater and flow through ventilation, lighter and ashtray, are right at hand on the console along with the shift selector. A no nonsense speedometer, trip odometer and matching tach are all present. Your auxiliary instruments are on a separate panel over the console- fuel, clock with sweep-second hand, oil pressure and amps, plus reminder lights for seat belts, door ajar and headlight doors.

Interior Options Available: A very complete cockpit comes standard on the 1975 Corvette, however more options were made available for those who wanted to order some factory-installed extras. Some of the optional interior features include: Tilt-Telescopic steering wheel, with seven tilt positions and six inches of telescopic travel, sure to include a steering wheel distance and angle that were just right for any enthusiast. Four-Season air conditioning, not only does it provide am integrated cooling, dehumidifying, heating, and ventilating function, but excellent circulation control. These controls are built right into the console, moreover. AM/FM radio with dual speakers and AM/FM/Stereo radio with dual speakers– both options were available add-ons for the 1975 Corvette, and it’s hard to go wrong with either one. Also available factory-installed are: Power windows, Rear window defogger (coupe only), Custom Deluxe shoulder belts  for convertible (color-keyed to your interior, Dual horns, Map light (mounted on inside rear-view mirror); includes a “head-lights on” warning buzzer. Also available were some dealer-installed accessories that could be decided on even after you take delivery. These items included: Citizen’s Band 23-channel radio, Right-hand outside mirror, Black floor mats, Compass, and Litter and Tissue container.  

The Corvette Chassis

By 1975 a whole generation of talented engineers had worked to develop and refine the remarkable Corvette chassis beyond its beginning in ’53.

Power Teams with Chevrolet’s new Efficiency System- A long way from the modified “Blue Flame” Six that was on the ’53. The ’75 boasted two 350 V8s, each with a new Efficiency System that’s designed to make Corvette run leaner (more economically),  cleaner (purer exhaust emission) and save you money every mile. The System includes Early Fuel Evaporation (for faster warm-up), outside air carburetion (for improved performance) among other things.

Standard 350 4-barrel V8- This is a rugged power plant with good low-speed torque, outstanding for around-town cruising. But in a trim Corvette chassis, it also becomes responsive and very willing when you put some road in front of it.

Available Special 350 4-barrel V8- The Special is also a 5-barrel, dual-exhaust 350, with all the new-for-’75 Efficiency System features. However, this one’s designed for more rugged work with a longer duration cam, special heads with larger valves, impact-extruded pistons, a forged crank, even six more bolts for the main bearing caps. To top it off, it’s graced with two of the prettiest, finned-aluminum rocket arm covers around.

High Energy Ignition- Standard on both engines, HEI has been under development for many years and was well worth waiting for. Solid-state circuitry eliminates a source of tune-up bother and expense: the points and condenser. Moreover, the circuitry, plus a special high energy ignition coil, provides a hotter, longer, duration spark which provides a hotter, longer duration spark which provides reliable firing and starting (especially in cold or wet weather) and helps extend the service life of the plugs. In short, HEI represents a major advancement in auto ignitions and one that’s sure to help keep your Corvette running like a Corvette.

Dual Exhausts With Catalytic Converter- You know the advantages of dual exhaust back pressure for improved engine performance. The catalytic converter part, however, is new. Essentially, it involves a core of platinum-palladium- coated porous pellets (the catalyst) which helps complete the oxidation of carbon monoxides and hydrocarbons. With the catalytic converter on the job, the factory can now tune your Corvette more toward performance and economy. Standard on both Corvette engines.

Standard Wide-Ratio 4-Speed Manual Transmission- This wide-ratio 4-Speed is a good choice for normal driving, which includes a lot of stop-and-go. The high first-gear ratio (2.64 to one) gets you off the mark smartly, and wide intermediate ratios provide good torque-matching at low and intermediate speeds. Moreover, there’s a nice, crisp shift action with all gears fully synchronized.

Available Turbo Hydramatic Transmission- The closer ratios of this 4-Speed are better suited for the numerous high-speed up-and-down-shifts, associated with off-road competitive driving. It’s fully synchronized with a first-gear ratio of 2.43 to one, Available only with the Special V8.

Available Turbo Hydramatic Transmission- Turbo Hydramatic is an automatic that gives you a choice. You can shift gear ranges manually with the selector on the console when you want added acceleration or engine braking. Or you can leave it in “Drive” to do its own thing. The torque converter plus automatic 3-speed gearbox provide up to a 5.2 to one ratio, making Turbo Hydra-matic an excellent stop-and-go performer. Available with either engine.

Rear Axle Ratios- When you’ve picked out the engine and transmission for your Corvette, select the rear axle ratio that suits your kind of driving. The standard ratio is recommended for most normal driving that will include a lot of in-town mileage. With the standard engine, if you’re planning to do a high percentage of cruising on expressways, specify the “Highway” ratio, since this lower numerical ratio reduces engine speed, giving better gas mileage. The “High-Altitude” ratio is best for hilly areas or for off-road competitive driving because this higher axle ratio permits higher engine speeds for added power. But you can also expect higher fuel consumption with the “High-Altitude” ratio.

Suspension- Corvette’s front suspension uses unequal-length upper and lower control arms, ball joints and coil springs, but with higher rate springs and a stabilizer bar to help boost road holding and stability.

However, it’s the independent rear suspension that really sets Corvette apart from other U.S. cars. The differential carrier is mounted to the Corvette frame, delivering its power to the wheels through half-axles and universal joints. The weight of the differential doesn’t move up and own with the rear wheels (as it must with a conventional solid rear axle). So the wheels can more freely follow the contours of the road for the added traction and road-holding you want from a sports car.

Also, the differential features Positraction which has the ability to direct most of the engine power to the rear wheel with the greater traction. An obvious advantage is in helping to reduce wheel spin on slippery pavements.

Tires? Naturally, they’re Corvette-specified steel-belted radials: GR70-15s mounted on 8-inch-wide rims that put plenty of stabilized tread area under your Corvette. Moreover, radials roll easier than conventional bias ply tires, so you may even get a slight bonus in gas mileage.

Available Suspensions- Gymkhana. A package designed to modify the standard suspension more to competition requirements. Includes higher rate front and rear springs (giving a firmer ride), a larger diameter front stabilizer bar and the addition of a rear stabilizer bar. This suspension is recommended only for the serious competitor. Off-Road. Includes everything in the Gymkhana package, plus heavy-duty power disc brakes. Also recommended only when off-road competitive driving is anticipated.

Brakes- For responsive braking, Corvette features a big 11.75″-diameter ventilated self-adjusting disc brake at each wheel. A hydraulic proportioning valve helps limit rear-wheel lock-up under heavy braking. Manual disc brakes (standard). Power-boosted disc brakes (available).

Steering- Parallel linkage and semi-reversible recirculating-ball-nut steering gear help give Corvette its excellent steering geometry and response plus a desirable level of road feel. There are two versions: Manual with 20.2 to one overall ratio (standard). Power with 17.6 to one overall ratio (available).

Frame. Note the large box-section side members… and the five crossmembers. This frame is built to do the job a Corvette has to do. Still, there are a couple of available items you might want to consider if you plan to pull a light boat or camping trailer (1,000 lbs. gross weight or less). Trailer frame hitch. Trailer wiring harness. Heavy-duty battery (to handle the extra electrical load).

Safety and Security Features- Occupant Protection- Two combination seat and (coupe only) shoulder belts with push-button buckles, reminder light and buzzer, starter interlock and (coupe only) shoulder belt inertia reels. Built-in head restraints. Safety steering wheel. Energy-absorbing steering column. Energy absorbing padded instrument panel, Padded sun visors, Passenger-guard door locks. Side-guard beams. Safety armrests. Folding seat back latches. Contoured windshield header (coupe only). Thick-laminate windshield. Accident Protection- Side marker lights and reflectors (front side marker lights flash with direction signal). Parking lights that illuminate with headlights. Four-way hazard warning flasher. Back-up lights. Lane-change feature in direction signal control. Windshield defrosters, washers, and dual-speed wipers. Wide-view inside day-night mirror (vinyl-edged, shatter-resistant glass and deflecting support). Outside rearview mirror. Dual master cylinder brake system with warning light. Starter safety switch. Anti-Theft- Anti-theft ignition key reminder buzzer. Anti-theft audio alarm system. Anti-theft steering column lock. Inside hood latch release.

Color Options: 

  • Classic White
  • Silver
  • Bright Blue
  • Steel Blue
  • Bright Green
  • Bright Yellow
  • Medium Saddle Metallic
  • Orange Flame
  • Dark Red
  • Mille Miglia Red

Interior Colors:

  • Black
  • Silver
  • Neutral
  • Dark Blue
  • Saddle
  • Dark Red

 

Mechanical Dimensions

Feature Convertible Coupe
Wheelbase 98 inches (2.489 m) 98 inches (2.489 m)
Overall length 185.5 inches (4.712 m) 185.5 inches (4.712 m)
Overall width 69.0 inches (1.753 m) 69.0 inches (1.753 m)
Overall height 47.4 inches (1.204 m)
Ground Clearance 4.5 inches (11.4 cm) 4.5 inches (11.4 cm)
Front tread 58.7 inches (1.491 m) 58.7 inches (1.491 m)
Rear tread 59.4 inches (1.509 m) 59.4 inches (1.509 m)
Tires F70-15 F70-15
Frame Full-length welded-steel 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, 39.0 turning circle
Rear axle type Sprung differential, Hypoid gear
Brakes Hydraulic, vented four wheel discs; 11.75-inch diameter, single calipers, optional power assist
Swept area 11.75″ front and back
Total swept area 461 sq. in.
Wheels 8″ wide slotted steel 15″ 5-lug disc
Standard rear axle ratio 3.36:1
Optional rear axle ratio 3.70:1, 3.08:1, 3.36:1, 3.55:1

 

 

Engine Specifications 

Feature Base Engine RPO ZQ3 RPO L82
Type V-8, Overhead valve
Block Cast iron block
Displacement 350 cid 350 cid
Bore & Stroke 4.00 x 3.48″ 4.00 x 3.48″
Compression ratio 8.5:1 9.0:1
Brake horsepower 165 @ 3800 205 @ 4800
Torque 255 lb-ft @ 2400 255 lb-ft @ 3600
Main bearing five
Valve lifters hydraulic
Camshaft High-performance camshaft
Fuel supply Rochester Quadra-Jet Four-BarrelModel 4MV Rochester Quadra-Jet Four-Barrel