🏷️ Basic Information

Make:

Chevrolet

Model:

Corvette

Year:

1968

Engine Variant:

396 Big-Block V8

Platform Code:

C3 (Third Generation)

👋 Introduction

Vehicle Segment:

American Sports Car / Grand Tourer

Target Audience:

Enthusiasts and owners of the 1968 Chevrolet Corvette, particularly those with the potent 396 Big-Block engine, seeking detailed maintenance and repair information.

Competitors 1968:

Ford Mustang, Jaguar E-Type, Shelby GT500, Pontiac Firebird, AMC Javelin.

Vehicle Key Features 1968:

Iconic C3 'Coke bottle' styling, powerful Big-Block V8 engine options, optional removable roof panels (T-tops), independent front suspension, rear independent suspension (first for Corvette), sophisticated fiberglass body construction.

Manual Benefit:

Empowers owners to perform essential maintenance and repairs, understand complex systems, and maintain their classic Corvette with factory-level accuracy and detail.

📋 Manual Details

Systems Covered:

All major mechanical and electrical systems, including engine, transmission, drivetrain, suspension, steering, brakes, body, interior, and HVAC.

Estimated Page Count:

~1000-1500 (typical for comprehensive workshop manuals of this era)

Manual Type:

Workshop Repair Service Manual

Language:

English

Format:

PDF Download

📖 Manual Coverage

Engine:

396 Big-Block V8 (L36 and L78 variants), including disassembly, inspection, assembly, tuning, and troubleshooting of all internal and external components.

Transmission:

Muncie M20/M21 4-speed manual transmission and Turbo Hydra-Matic TH400 automatic transmission, including overhaul, adjustments, and diagnostics.

Drivetrain:

Rear axle, driveshaft, CV joints (if applicable for certain configurations), and wheel bearings.

Suspension:

Independent front suspension (upper and lower control arms, ball joints, kingpins, coil springs), rear transverse leaf spring, trailing arms, and shock absorbers.

Steering:

Power steering system (pump, hoses, steering gearbox), steering column, and linkages.

Brakes:

Front disc brakes (calipers, rotors, pads), rear drum brakes, master cylinder, power brake booster, and brake lines.

Electrical:

Ignition system (distributor, coils, spark plugs), charging system (alternator, voltage regulator), starting system (starter motor, solenoid), lighting, gauges, horn, wipers, and radio.

Body And Interior:

Frame, body panels, doors, windows, convertible top, seats, dashboard, trim, and weatherstripping.

HVAC:

Heater and defroster systems, air conditioning components (if equipped).

Maintenance:

Scheduled maintenance, oil changes, filter replacements, tune-ups, lubrication, and fluid checks.

Troubleshooting:

Diagnostic charts and procedures for identifying and resolving common problems across all vehicle systems.

Repair:

Detailed step-by-step instructions for component removal, repair, and reinstallation for virtually all parts of the vehicle.

Diagnostics:

Procedures for diagnosing electrical, mechanical, and performance issues, often including symptom-based troubleshooting.

Disassembly Assembly:

Comprehensive instructions for complete engine and transmission rebuilds, as well as component-level disassembly and reassembly.

Specifications And Tolerances:

Critical dimensions, clearances, torque values, and alignment specifications for accurate repairs.

Depth Of Information:

Comprehensive and highly detailed, suitable for professional mechanics and serious DIY enthusiasts. Covers everything from basic fluid checks to complete engine and transmission overhauls.

Diagnostic Techniques:

Advanced diagnostic procedures for electrical systems, fuel delivery, ignition timing, and engine performance issues using period-appropriate tools and methods.

Special Tools:

Identification and usage of specialized tools required for specific repair procedures, often with diagrams.

📊 Manual Specifications

File Type:

PDF

Searchability:

Likely text-searchable if created from a high-quality scan of an original manual.

Digital Quality:

Variable, dependent on original scan quality. A good quality PDF will offer clear diagrams and readable text.

Binding Type:

N/A (Digital Download)

Paper Type:

N/A (Digital Download)

⚙️ Engine Specifications

Engine Code And Displacement:

396 cu in (6.5 L) V8 (RPO L36: 325 hp; RPO L78: 390 hp)

Horsepower L36:

325 hp @ 4,800 rpm

Torque L36:

410 lb-ft @ 3,200 rpm

Horsepower L78:

390 hp @ 5,600 rpm

Torque L78:

430 lb-ft @ 3,600 rpm

Carburetion:

L36: Rochester Quadrajet 4-barrel carburetor; L78: Holley 780 cfm 4-barrel carburetor

Fuel Type:

Premium Unleaded Gasoline (approx. 91-93 octane)

Block Material:

Cast Iron

Cylinder Head Material:

Cast Iron

Bore X Stroke:

4.25 in x 3.48 in (108 mm x 88.4 mm)

Compression Ratio L36:

10.25:1

Compression Ratio L78:

11.0:1

Valvetrain:

Overhead Valve (OHV), 2 valves per cylinder, hydraulic lifters (L36), solid lifters (L78)

🔧 Transmission

Standard Transmission:

Muncie M20/M21 4-speed manual (often standard with 396)

Optional Transmission:

Turbo Hydra-Matic TH400 3-speed automatic

Manual Gear Ratios:

M20: Close-ratio (e.g., 2.52, 1.88, 1.42, 1.00); M21: Wider-ratio (e.g., 2.20, 1.66, 1.31, 1.00) - specific ratios may vary, consult manual for exact specifications.

Automatic Transmission Features:

Torque converter, planetary gearsets, hydraulic control system.

Manual Transmission Fluid:

GL-4 Gear Oil (e.g., SAE 80W/90 or SAE 75W-90 synthetic GL-4)

Automatic Transmission Fluid:

Dexron III (or equivalent) Automatic Transmission Fluid (ATF)

📐 Dimensions

Length:

175.1 inches (4448 mm)

Width:

69.1 inches (1755 mm)

Height:

47.5 inches (1207 mm) (Coupe), 47.1 inches (1196 mm) (Convertible)

Wheelbase:

98.0 inches (2489 mm)

Curb Weight:

Approximately 3,300 - 3,500 lbs (1497 - 1588 kg), depending on options.

Gross Vehicle Weight Rating:

Not typically specified for sports cars of this era, but engine/transmission choices affect overall weight distribution.

Cargo Volume:

Limited, primarily behind the seats and in the rear storage compartment (Convertible).

🛡️ Safety Features

Crash Test Ratings:

No standardized crash test ratings existed in the modern sense for vehicles of this era.

Active Safety Features:

Disc brakes on all four wheels (standard), power steering (optional), strong chassis design.

Passive Safety Features:

Steel frame construction, padded dashboard (early stages of development), lap belts (standard), shoulder belts (optional/dealer-installed in some cases).

Safety Considerations:

Outdated safety technology compared to modern vehicles. Potential for fuel system leaks, braking system wear, and steering component wear require regular inspection.

💡 Technology Features

Infotainment System 1968:

Primarily AM/FM radio (mono or stereo optional), with some models featuring 8-track tape players. No digital displays or navigation.

Driver Assistance Features 1968:

None in the modern sense. Features like power brakes and power steering were considered advanced conveniences.

🔧 Maintenance

Oil Change Interval:

Typically every 3,000-5,000 miles or every 6 months (whichever comes first), depending on driving conditions. Consult manual for specific recommendations.

Tune Up Interval:

Spark plugs, points, and condenser inspection/replacement every 10,000-15,000 miles. Distributor timing adjustment as needed.

Transmission Fluid Change:

Automatic: Every 24,000-36,000 miles. Manual: Inspect periodically, change if contaminated or milky.

Engine Oil Capacity:

5 US quarts (4.7 liters) with filter (396 Big-Block).

Engine Oil Type:

API SG or SH service classification, SAE 10W-30 or 10W-40 recommended for general use. Consult manual for specific weight and additive recommendations for flat-tappet camshafts.

Coolant Capacity:

Approximately 20-22 US quarts (19-21 liters) for V8 models.

Coolant Type:

Ethylene glycol-based antifreeze and water mixture (50/50).

Brake Fluid Type:

DOT 3 or DOT 4 hydraulic brake fluid.

Common Issues Engine:

Oil leaks (valve covers, oil pan, rear main seal), carburetor tuning issues, ignition system wear (points, condenser, coil), exhaust manifold leaks, potential for camshaft lobe wear (due to older oil formulations without ZDDP).

Common Issues Chassis:

Suspension bushing wear, ball joint wear, steering gearbox leaks, U-joint wear, wheel bearing noise, brake component wear (pads, rotors, drums), electrical connector corrosion.

Common Issues Body:

Fiberglass cracks or spider-webbing, door alignment issues, weatherstrip deterioration, convertible top frame wear or leaks, frame rust (in certain climates).

📚 Vehicle History

Chevrolet Heritage:

Chevrolet, founded in 1911, has a long history of producing iconic American cars, with the Corvette being its flagship sports car introduced in 1953.

Corvette C3 Introduction:

The C3 generation debuted for the 1968 model year, marking a significant departure in styling from the C2 Sting Ray, featuring the distinctive 'Mako Shark' design language.

Corvette C3 1968 Highlights:

Introduction of the C3 body style, wider range of engine options including the 396 Big-Block, optional T-tops, and a shift towards a more luxurious GT feel alongside its sports car performance.

Production Years C3:

1968-1982

Manufacturing Location 1968:

St. Louis, Missouri, USA

Corvette 396 Production Period:

The 396 Big-Block was offered in the Corvette for a limited period, primarily from 1968-1969 before being replaced by the 427.

🏆 Awards & Recognition

Vehicle Recognitions 1968:

The C3 Corvette was generally well-received for its radical new styling and performance capabilities, becoming a symbol of American automotive design and power.

Performance Ratings 1968:

Praised for its potent engine options and handling characteristics, though criticized by some for its initial rough ride and complex body construction.

Certification Standards 1968:

Adhered to all applicable US Federal Motor Vehicle Safety Standards (FMVSS) of the era.