🏷️ Basic Information

Make:

Chevrolet

Model:

Corvette

Year:

1968

Engine Codes Covered:

L36 (396 cu in), L68 (427 cu in), L71 (427 cu in), L89 (427 cu in), L72 (427 cu in), LS1 (350 cu in), L30 (327 cu in), L36 (327 cu in), L46 (350 cu in), L48 (350 cu in), L65 (350 cu in), L79 (327 cu in), L88 (427 cu in - specialized reference)

Generation Name:

C3 (Third Generation)

Generation Years:

1968-1982

👋 Introduction

Vehicle Class:

Sports Car

Target Audience:

Enthusiasts, restorers, mechanics specializing in classic American muscle and sports cars

Key Competitors 1968:

Ford Mustang (performance variants), Pontiac Firebird, Dodge Charger

Vehicle Highlights:

Iconic styling, powerful V8 engine options, independent suspension, high performance potential, a defining model of American sports car engineering

Manual Benefit:

Essential for proper maintenance, troubleshooting, and restoration of a classic vehicle, preserving its value and performance

📋 Manual Details

Engine:

All listed V8 engine variants (305 cu in interpretation is likely a typo for 327 or 350 as 305 was not a 1968 Corvette option)

Transmission:

Manual (Muncie M20, M21, M22), Automatic (Turbo Hydra-Matic 400)

Chassis:

Frame, suspension (front and rear independent), steering, brakes (disc front/rear)

Electrical:

Wiring diagrams, lighting, ignition, starting, charging, instrumentation, accessories

Body:

Exterior body panels, interior trim, weatherstripping, convertible top mechanism

Miscellaneous:

HVAC system, fuel system, cooling system, exhaust system

Estimated Page Count:

Approximately 800-1200+ pages (typical for a comprehensive factory service manual)

Manual Type:

Workshop Repair Service Manual

Language:

English

Format:

PDF Download

📖 Manual Coverage

Engine Mechanical:

Engine disassembly, inspection, repair, assembly for all specified V8 displacements (e.g., crankshaft, pistons, rings, connecting rods, cylinder heads, valves, camshaft, timing set, oil pump, lubrication system)

Fuel And Emissions:

Carburetor systems (e.g., Rochester Quadrajet, Holley), fuel pumps, fuel lines, fuel tank, emissions control systems (if applicable for late 1968 models)

Ignition System:

Distributor, ignition coil, spark plugs, points and condenser (or early electronic ignition if equipped), timing adjustments

Cooling System:

Radiator, fan, water pump, thermostat, coolant types and capacities

Transmission Manual:

Muncie four-speed transmission (M20, M21, M22) - disassembly, repair, fluid types, capacity, shift linkage adjustment

Transmission Automatic:

Turbo Hydra-Matic 400 - disassembly, repair, fluid types, capacity, torque converter, linkage adjustment

Drivetrain:

Clutch assembly, driveshaft, U-joints, rear axle differential (e.g., limited-slip options), axle ratio information, wheel bearings

Suspension Steering:

Front independent suspension (upper/lower control arms, ball joints, tie rods, bushings), rear independent suspension (trailing arms, universal joints, transverse leaf spring), power steering system (pump, gearbox, hoses), steering column

Brakes:

Front and rear disc brake system (calipers, rotors, pads, master cylinder, brake fluid specifications, bleeding procedures, parking brake)

Electrical System:

Detailed wiring diagrams by circuit, component testing, troubleshooting, starter motor, alternator (or generator), battery specifications, fuses, relays, lighting circuits, horn, wipers, power windows (if equipped)

Body And Trim:

Body panel repair, dent removal, rust repair techniques, door mechanisms, window regulators, hood latch, convertible top operation and repair, interior panel removal and installation, seat adjustment and repair

Routine Maintenance:

Oil changes, filter replacements, spark plug replacement, fluid level checks and top-offs, lubrication points

Troubleshooting:

Diagnostic procedures for engine performance, electrical faults, braking issues, transmission problems, starting and charging system issues, based on symptom analysis

Component Rebuilds:

Detailed instructions for the complete disassembly, cleaning, inspection, repair, and reassembly of major components like engines, transmissions, carburetors, brake calipers, and rear differentials

Diagnostics:

Testing procedures for electrical components, fuel systems, ignition timing, and mechanical wear using appropriate tools and specifications

Adjustments:

Ignition timing, carburetor idle and mixture, clutch linkage, parking brake, valve lash (for some engines)

Depth Level:

Comprehensive rebuilds, advanced diagnostics, detailed specifications, factory-recommended procedures

Diagnostic Tools:

Mentions or implies use of standard automotive tools, feeler gauges, timing lights, multimeters, compression testers

Repair Techniques:

Detailed step-by-step instructions with torque specifications, clearances, and critical measurements for all repair operations

📊 Manual Specifications

File Type:

PDF

Searchability:

Typically searchable text-based PDF (depending on source digitization quality)

Printability:

Printable pages

Digital Quality:

High-resolution scans of original factory service manuals or factory data

Quality Description:

N/A for PDF download, but implies clarity and legibility of original documents.

Binding Type:

N/A for PDF download

Paper Type:

N/A for PDF download

Completeness Level:

Comprehensive (covers all major systems and repairs for the specified model year and engine options)

⚙️ Engine Specifications

Base Engine 1968:

350 cu in (5.7L) V8 (L48, L65, LS1)

Available Engines:

327 cu in (5.4L) V8 (L30, L36, L79), 396 cu in (6.5L) V8 (L36), 427 cu in (7.0L) V8 (L68, L71, L89, L72, L88)

Horsepower Range:

Approx. 300 HP (base 350) to 430+ HP (L88 427, rated)

Torque Range:

Approx. 360 lb-ft to 460+ lb-ft

Carburetion:

Single 4-barrel Rochester Quadrajet (most engines), Dual 4-barrel Holley carburetors (some performance 427s), Single 2-barrel Rochester (base 327)

Fuel Type:

Premium Unleaded Gasoline (Octane rating varies by engine, typically 91+)

Cooling Capacity:

Approx. 5-6 gallons (engine dependent)

Oil Capacity:

Approx. 5 quarts (with filter) for 327/350, 6 quarts for 396/427

🔧 Transmission

Standard Transmission 1968:

Muncie M20 4-Speed Manual

Optional Transmission 1968:

Muncie M21 4-Speed Manual (close-ratio), Muncie M22 'Rock Crusher' 4-Speed Manual (heavy-duty), Turbo Hydra-Matic 400 3-Speed Automatic

Automatic Transmission Features:

Stall converter, variable throttle valve for shift feel

Manual Transmission Fluid Spec:

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

Automatic Transmission Fluid Spec:

Dexron III (or equivalent type 'A' Suffix 'A' historically, now superseded)

📐 Dimensions

Overall Length:

175.1 inches (4448 mm)

Overall Width:

69.2 inches (1758 mm)

Overall Height:

47.7 inches (1212 mm) (Coupe), 46.6 inches (1184 mm) (Convertible)

Wheelbase:

98.0 inches (2489 mm)

Curb Weight Range:

Approx. 3,400 - 3,800 lbs (depending on engine and options)

Gross Vehicle Weight Rating Gvwr:

Not typically published for performance sports cars of this era, focus on chassis load limits.

Standard Wheel Size:

15 x 7 inches

Standard Tire Size:

F70-15 (Bias-ply whitewall or blackwall)

Bolt Pattern:

5 x 4.75 inches (5 x 120.65 mm)

🛡️ Safety Features

Crash Test Ratings:

NHTSA ratings not applicable for 1968 models; safety features were less standardized than modern vehicles.

Active Safety Features:

Four-wheel disc brakes, independent suspension for better handling

Passive Safety Features:

Lap belts (standard), optional shoulder belts, padded interior surfaces (dashboard, steering wheel hub), shatter-resistant windshield

💡 Technology Features

Infotainment System:

AM/FM Radio (mono or with optional FM stereo), often with 8-track tape player integration as an option. Basic instrumentation (speedometer, tachometer, oil pressure, water temperature, ammeter, fuel gauge).

Driver Assistance Features:

None in the modern sense. Relied on driver skill and mechanical systems.

Comfort Features:

Optional air conditioning, power windows, tilt-telescopic steering wheel, vinyl or leather seating options

🔧 Maintenance

Oil Change Interval:

Every 3,000-5,000 miles or annually, depending on usage and oil quality (modern synthetic oils may allow longer intervals but older engines may benefit from more frequent changes)

Tune Up Interval:

Recommended every 12,000-24,000 miles, including spark plug, points (if applicable), condenser, distributor cap/rotor replacement, and ignition timing adjustment

Transmission Fluid Change:

Every 20,000-30,000 miles for automatic, often based on inspection for manual transmissions.

Engine Oil Specification:

API SF/SG rated oils, viscosity typically SAE 10W-30 or SAE 10W-40 (check manual for specific recommendations based on temperature range). Zinc additives (ZDDP) are often recommended for flat-tappet camshaft engines.

Brake Fluid Specification:

DOT 3 or DOT 4 brake fluid (glycol-based)

Coolant Specification:

Ethylene glycol based antifreeze, typically a 50/50 mix with distilled water. Traditional green coolant.

Common Wear Items:

U-joints, ball joints, tie rod ends, universal joints in drive axles, clutch components, starter motor, alternator, carburetor wear (e.g., accelerator pump seals, power piston seals), vacuum leaks

Common Problem Areas:

Electrical system gremlins (corrosion, faulty grounds), C3 specific frame/chassis rust (especially around T-tops if applicable on later models, but frame rot is general), fiberglass body crack propagation, weatherstripping degradation leading to leaks, carburetors requiring frequent adjustment/rebuilding

📚 Vehicle History

Chevrolet Legacy:

Founded in 1911, Chevrolet has a long history of producing a wide range of vehicles, from economy cars to performance icons. The Corvette, introduced in 1953, became its flagship sports car.

Corvette C3 Introduction:

The C3 generation, introduced for the 1968 model year, represented a significant departure in styling from the C2 (Sting Ray) with its distinctive Coke-bottle shape, concealed headlights, and pronounced fender flares.

1968 Model Year Changes:

First year of the C3. Introduction of the 350 cubic inch engine as a base option. Revised interior, new door handles, and increased wheelbase compared to previous generations. Early 1968 models retained some C2 features (e.g., non-retracting headlights on early production units).

Production Location:

St. Louis, Missouri, USA

1968 Production Volume:

28,566 units

🏆 Awards & Recognition

Historic Significance:

The C3 Corvette is a highly collectible and iconic American sports car, representing a significant era in automotive design and performance. Often featured in automotive magazines and awarded at car shows.