🏷️ Basic Information

Make:

Chevrolet

Model:

Corvette

Year:

1968

Engine Options Covered:

350 cubic inch V8, 396 cubic inch V8

Trim Levels Covered:

All

Transmission Options Covered:

All

Vin Code Engine 1:

LM1 (350ci/300hp)

Vin Code Engine 2:

L46 (350ci/350hp)

Vin Code Engine 3:

L71 (427ci/400hp - likely incorrect as manual specifies 350/396, but 427 was available)

Vin Code Engine 4:

L36 (427ci/390hp - likely incorrect as manual specifies 350/396, but 427 was available)

Vin Code Engine 5:

L68 (427ci/390hp - likely incorrect as manual specifies 350/396, but 427 was available)

Vin Code Engine 6:

L72 (427ci/430hp - likely incorrect as manual specifies 350/396, but 427 was available)

👋 Introduction

Vehicle Segment:

Sports Car / Personal Luxury Coupe

Target Audience:

Enthusiasts seeking performance, style, and a premium driving experience.

Key Competitors:

Ford Mustang (performance variants), Porsche 911 (higher-end competition), Jaguar E-Type (styling and performance)

Design Philosophy:

Iconic Stingray design, driver-focused cockpit, powerful V8 engine options.

Performance Orientation:

Emphasis on acceleration, handling, and road-holding capabilities for its era.

Collectible Status:

Highly sought-after collector car, representing a significant era in American automotive history.

📋 Manual Details

Overall Coverage:

Comprehensive service, maintenance, and troubleshooting for all 1968 Chevrolet Corvette models equipped with 350 and 396ci V8 engines.

Specific Coverage:

Engine overhaul, transmission repair, brake systems, suspension, steering, electrical diagnostics, body and chassis repairs, climate control, fuel and exhaust systems.

Estimated Page Count:

Approximately 800-1000 pages (typical for comprehensive workshop manuals of this era, actual may vary based on PDF compression and inclusion of supplementary data).

Type:

Workshop Repair Service Manual

Purpose:

Designed for professional technicians and experienced DIY enthusiasts.

Language:

English

Format:

PDF Download

📖 Manual Coverage

Engine Mechanical:

Detailed procedures for engine disassembly, inspection, reassembly, torque specifications, timing, valve adjustment, piston ring installation, crankshaft bearing service, and cylinder head overhaul.

Fuel System:

Carburetor (Holley/Rochester Quadrajet) tuning and rebuilding, fuel pump testing and replacement, fuel line routing and inspection, fuel tank servicing.

Ignition System:

Distributor service, ignition timing adjustment, spark plug selection and gap, coil testing, troubleshooting ignition component failures.

Cooling System:

Radiator service, water pump inspection and replacement, thermostat testing, coolant type specifications, fan belt adjustment, troubleshooting overheating issues.

Exhaust System:

Exhaust manifold gasket replacement, muffler and pipe inspection and repair, catalytic converter (if applicable for specific export markets, unlikely for US domestic 1968).

Transmission Manual:

Muncie 4-speed transmission (M20, M21, M22 'Rock Crusher') overhaul, clutch adjustment and replacement, gear oil specifications.

Transmission Automatic:

Turbo-Hydra-Matic 350 (THM350) service, fluid type and capacity, band adjustment, troubleshooting common automatic transmission faults.

Drivetrain:

Driveshaft service, U-joint replacement, rear axle inspection and lubrication, differential gear ratio identification.

Suspension Front:

Ball joint replacement, control arm bushings, tie rod end service, shock absorber replacement, spring inspection, wheel alignment specifications.

Suspension Rear:

Transverse leaf spring service, trailing arm bushings, shock absorber replacement, U-joint inspection.

Steering:

Power steering system troubleshooting, steering box adjustment and repair, tie rod and idler arm replacement, steering column service.

Brakes Front:

Front disc brake caliper overhaul, brake pad replacement, rotor inspection and resurfacing, brake fluid specifications.

Brakes Rear:

Rear drum brake adjustment and shoe replacement, wheel cylinder service, brake drum inspection.

Electrical System:

Wiring diagrams for all systems, alternator testing and replacement, starter motor service, battery maintenance, fuse and circuit breaker identification, lighting system troubleshooting, instrument cluster repair.

Body And Chassis:

Door hinge adjustment, window regulator repair, seat mounting, exterior trim replacement, frame inspection, rust prevention and repair guidance.

Climate Control:

Heater core service, vent control operation, blower motor troubleshooting (Note: Factory A/C was less common on base models but may be covered).

Preventative Maintenance:

Detailed oil change intervals, filter replacement procedures, lubrication points, tune-up specifications, coolant flushes, brake fluid replacement.

Troubleshooting:

Systematic diagnostic charts for common drivability issues, electrical faults, braking problems, and mechanical noise identification.

Engine Repair:

Complete engine rebuild procedures, including machining tolerances, component specifications, and assembly sequences.

Transmission Repair:

Step-by-step guides for complete transmission overhaul, seal replacement, and clutch assembly.

Electrical Diagnostics:

Detailed use of wiring diagrams, multimeter testing procedures, and component testing methods for all electrical circuits.

Chassis Repair:

Procedures for replacing wear items like ball joints, bushings, and tie rod ends, along with alignment adjustments.

Bodywork Procedures:

Guidance on interior trim removal and installation, window adjustments, and minor body panel alignment.

Depth Level:

In-depth, covering complete vehicle teardown and reassembly, advanced diagnostics, and component-level repair.

Component Rebuilds:

Covers rebuilding of major components such as engines, transmissions, carburetors, distributors, alternators, and brake calipers.

Diagnostic Tools:

Implied use of standard mechanic's tools and basic electrical diagnostic equipment (multimeter, timing light).

📊 Manual Specifications

Format:

PDF

Searchability:

Likely text-searchable, allowing for quick keyword identification.

Image Resolution:

Variable depending on source scan, but professional manuals aim for clear diagrams and legible text.

Diagram Clarity:

Expected to include detailed exploded views, wiring diagrams, and schematic illustrations.

Binding:

N/A (Digital Format)

Paper Type:

N/A (Digital Format)

⚙️ Engine Specifications

Base Engine:

350 cubic inch (5.7L) V8

Optional Engine 1:

396 cubic inch (6.5L) V8 (Note: The 396 was typically a Chevrolet big-block, however, Chevrolet did offer a 350 small-block. The manual specifying '350 396' might imply coverage for both a common small-block and the rarer big-block option available in '68, or a simplification. For clarity, the 396 engine code was L35 for the Corvette in 1968, producing 325 hp).

350 Hp Rating 1:

300 hp (LM1)

350 Hp Rating 2:

350 hp (L46)

396 Hp Rating:

325 hp (L35) (Note: This is the commonly cited figure for the 396 in the Corvette for 1968).

Torque Rating 350 1:

360 lb-ft @ 3200 RPM (LM1)

Torque Rating 350 2:

375 lb-ft @ 3600 RPM (L46)

Torque Rating 396:

400 lb-ft @ 3200 RPM (L35)

Carburetion 350:

Rochester Quadrajet 4-barrel (LM1, L46)

Carburetion 396:

Holley 4160 4-barrel (L35)

Fuel Type:

Premium Unleaded Gasoline (91 Octane or higher recommended)

Block Material 350:

Cast Iron

Block Material 396:

Cast Iron

Cylinder Heads:

Cast Iron with 2.02-inch intake valves (L46) or 1.94-inch intake valves (LM1); Cast Iron for 396.

Compression Ratio 350 1:

10.25:1 (LM1)

Compression Ratio 350 2:

11.0:1 (L46)

Compression Ratio 396:

10.25:1 (L35)

🔧 Transmission

Standard Transmission Type:

Muncie 4-Speed Manual (M20, M21, M22 options)

Optional Transmission Type:

Turbo-Hydra-Matic 350 (3-Speed Automatic)

Manual Gear Ratios:

Varied by Muncie model (e.g., M20 close ratio, M21 wide ratio, M22 heavy-duty ratios available, specified in manual).

Automatic Gear Ratios:

1st: 2.52:1, 2nd: 1.52:1, 3rd: 1.00:1 (THM350)

Clutch Type:

Single Dry Plate (Manual Transmission)

Manual Transmission Fluid:

GL-4 Hypoid Gear Lubricant (e.g., SAE 80W-90)

Automatic Transmission Fluid:

Dexron III (or equivalent specification for its era, e.g., Type A Suffix A transmission fluid), approximately 9-10 quarts capacity.

📐 Dimensions

Length:

175.0 inches (4445 mm)

Width:

69.0 inches (1753 mm)

Height:

47.7 inches (1212 mm)

Wheelbase:

98.0 inches (2489 mm)

Front Track:

55.7 inches (1415 mm)

Rear Track:

56.5 inches (1435 mm)

Ground Clearance:

Approx. 5.0 inches (127 mm)

Curb Weight:

Approx. 3,300 - 3,600 lbs (1497 - 1633 kg), depending on engine and options.

Gross Vehicle Weight Rating:

Not typically specified in the same way as modern vehicles; refer to chassis load limits in manual.

Cargo Volume:

Rear storage compartment behind seats, limited space.

🛡️ Safety Features

Crash Test Ratings:

N/A (No standardized crash testing existed in the modern sense for 1968 vehicles).

Braking System:

Power-assisted 4-wheel disc brakes standard.

Steering System:

Recirculating ball steering, optional power steering.

Seat Belts:

Standard lap belts; shoulder belts often optional or dealer-installed, depending on market and build date.

Body Construction:

Fiberglass reinforced plastic body over a steel backbone chassis.

Windshield:

Laminated safety glass.

💡 Technology Features

Radio Options:

AM/FM radio, often with an 8-track tape player as an option. Speakers were typically door-mounted and dash-mounted.

Dashboard Design:

Driver-centric layout with prominent tachometer and speedometer, auxiliary gauges integrated into the center console.

🔧 Maintenance

Oil Change Interval:

Every 3,000-4,000 miles or 6 months, whichever comes first.

Tune Up Interval:

Every 10,000-15,000 miles or annually, including spark plug replacement, ignition timing adjustment, carburetor adjustment.

Transmission Service Interval:

Automatic transmission fluid and filter change every 24,000-30,000 miles; manual transmission fluid check and flush every 30,000-40,000 miles.

Coolant Flush Interval:

Every 2 years or 30,000 miles.

Engine Oil Type:

API SF/CD rated, SAE 10W-30 or 10W-40 depending on ambient temperature. For high-performance or older engines, a ZDDP additive is often recommended.

Engine Oil Capacity:

Approximately 5 quarts (with filter) for 350ci; 6 quarts (with filter) for 396ci and 427ci.

Brake Fluid Type:

DOT 3 or DOT 4 Hydraulic Brake Fluid.

Power Steering Fluid:

Dexron III (or equivalent) or specific power steering fluid.

Engine Oil Leaks:

Common from valve cover gaskets, oil pan gaskets, and rear main seals due to age and material degradation.

Carburetor Performance:

Rochester Quadrajet and Holley carburetors can develop worn throttle shafts, vacuum leaks, and require regular rebuilding/adjustment.

Ignition System Reliability:

Points-style ignition systems require regular adjustment and component replacement (points, condenser, rotor, cap). Electronic ignition conversion is a common upgrade.

Fiberglass Body Cracks:

Cracks can develop around stress points, especially near suspension mounts and door openings.

Vacuum Actuated Headlights:

The vacuum-operated headlight doors are a common failure point, requiring vacuum line inspection and actuator diaphragm replacement.

Suspension Wear:

Ball joints, tie rod ends, and bushings are common wear items requiring periodic replacement to maintain proper alignment and handling.

📚 Vehicle History

Chevrolet Legacy:

Chevrolet, a division of General Motors, has a long history of producing iconic American vehicles, particularly performance-oriented models.

Corvette Generations:

1968 marked the first year of the C3 generation (often referred to as the 'Mako Shark' or 'Shark' body style), which ran from 1968-1982. This was a significant redesign from the C2 Sting Ray.

1968 Specifics:

Introduction of the C3 body, the side-pipe exhaust option (deleted later in the year due to noise regulations), and the first availability of the 350 small-block V8 in the Corvette.

Production Location:

St. Louis, Missouri, USA

Production Volume 1968:

Approximately 28,566 Corvettes produced for the 1968 model year.

🏆 Awards & Recognition

Model Acclaim:

The C3 Corvette is widely recognized as an automotive icon, celebrated for its design and performance heritage. While specific awards for the 1968 model year might not be cataloged in the same way as modern vehicles, its cultural impact and enduring desirability are testament to its success.

Automotive Journalism:

Contemporary reviews praised the C3's aggressive styling and improved handling over its predecessor, though some noted a firm ride and early production quality concerns.

Historic Vehicle Status:

Many 1968 Corvettes qualify for historic vehicle registration and associated benefits in various regions, acknowledging their collectible status.