🏷️ Basic Information

Make:

Chevrolet

Model:

Corvette

Year:

1968

Trim Level:

427

Vin Structure:

1968 Corvette VINs typically start with '194', '195', or '196' depending on body style and engine, followed by a sequential production number.

👋 Introduction

Positioning:

The 1968 Corvette 427 represented the pinnacle of American performance for its era, a halo car aimed at enthusiasts and a symbol of automotive muscle. It competed directly with other high-performance sports cars and muscle cars of the period.

Competitors:

Key competitors included Ford Mustang (performance variants), Plymouth Barracuda (performance variants), Dodge Charger (performance variants), and European sports cars like Porsche 911, Jaguar E-Type, and Chevrolet's own higher-performance Camaros.

Features:

Iconic C3 Stingray body style, powerful 427 cubic inch V8 engines, advanced (for its time) independent suspension, convertible and coupe body styles, luxurious interior appointments, and a strong performance heritage.

📋 Manual Details

Coverage:

All Models, Engines, Trim Levels, and Transmission Types for the 1968 Corvette 427

Page Count:

Detailed and extensive, likely exceeding 500 pages based on the comprehensive nature of professional workshop manuals for this era.

Type:

Workshop Repair Service Manual

Language:

English

Format:

PDF Download

📖 Manual Coverage

Engine:

Complete overhaul and repair procedures for all 427 cubic inch V8 engine variants, including L36, L68, L71, L88, and L89. Includes engine assembly, disassembly, cooling system, lubrication system, fuel system, ignition system, emission controls (where applicable for the era).

Transmission:

Detailed coverage of the Muncie M20, M21, and M22 4-speed manual transmissions, and the Turbo-Hydramatic 400 (TH400) automatic transmission. Includes overhaul, adjustments, clutch service, and fluid specifications.

Drivetrain:

Rear axle assembly (Positraction and open differential options), drive shafts, U-joints, and half-shafts. Includes inspection, lubrication, and repair.

Suspension:

Front and rear independent suspension systems. Covers coil springs, control arms, ball joints, tie rod ends, shock absorbers, sway bars, and wheel bearings. Includes alignment specifications.

Brakes:

Front and rear hydraulic drum brakes and optional front disc brakes (standard on 427 models). Includes master cylinder, wheel cylinders, brake lines, calipers, pads/shoes, parking brake system, and fluid specifications.

Steering:

Manual steering and optional power steering systems. Includes steering box, linkages, power steering pump, hoses, and fluid specifications.

Electrical:

Complete electrical system schematics, troubleshooting, and repair. Covers battery, charging system (alternator), starting system (starter motor), ignition system (distributor, coil, plugs), lighting (headlights, taillights, interior), gauges, switches, and wiring harnesses. Includes component testing and diagnosis.

Body:

Body construction, sheet metal repair, doors, hood, trunk lid, bumpers, glass, weatherstripping, and interior trim. Includes body panel alignment and repair techniques.

HVAC:

Heater system and optional air conditioning system. Includes blower motor, heater core, evaporator core, refrigerant system components, and controls.

Maintenance:

Detailed recommended maintenance schedules, oil changes, filter replacements, fluid checks and top-offs, lubrication points, tune-up procedures, and component inspection.

Troubleshooting:

Systematic diagnostic procedures for common and uncommon issues across all vehicle systems. Includes symptom-based troubleshooting guides and diagnostic flowcharts.

Repair:

Step-by-step instructions for component removal, disassembly, cleaning, inspection, repair, assembly, and reinstallation for all major vehicle systems.

Rebuilds:

Comprehensive instructions for complete engine, transmission, carburetor, and differential rebuilds, including detailed specifications and tolerances.

Adjustments:

Precise procedures for adjusting carburetor idle speed and mixture, ignition timing, clutch pedal free play, brake pedal travel, and parking brake.

Specifications:

Torque specifications for all fasteners, engine bearing clearances, piston ring end gap, valve lash adjustments, ignition timing settings, and more.

Depth:

Extremely detailed, covering everything from basic preventative maintenance and fluid changes to complete engine and transmission overhauls, complex electrical diagnostics, and body repair.

📊 Manual Specifications

PDF Quality:

High-resolution, likely scanned from original factory manuals, ensuring clarity of diagrams, illustrations, and text. Searchable text capability is common for professionally prepared PDFs.

Printable:

Yes, the PDF format allows for selective or full printing of pages.

Binding:

N/A (Digital PDF format)

Paper Type:

N/A (Digital PDF format)

⚙️ Engine Specifications

Engine Family:

Chevrolet Big-Block V8 (427 cubic inch)

Base Engine L36:

390 hp @ 5200 rpm, 470 lb-ft torque @ 3600 rpm. Cast-iron heads, 10.25:1 compression, 4-bbl carburetor (Holley 780 cfm).

Engine L68:

400 hp @ 5400 rpm, 460 lb-ft torque @ 3800 rpm. Cast-iron heads, 10.25:1 compression, 3x2-bbl carburetors (Rochester Tri-Power).

Engine L71:

435 hp @ 5800 rpm, 460 lb-ft torque @ 4000 rpm. Cast-iron heads, 11.0:1 compression, 3x2-bbl carburetors (Rochester Tri-Power), high-performance camshaft.

Engine L88:

430 hp (gross rating, actual significantly higher), 470 lb-ft torque. Aluminum heads, 12.5:1 compression, 850 cfm Holley 4-bbl carburetor. Designed for racing, aggressive camshaft, often considered a dealer-installed option or special order.

Engine L89:

435 hp @ 5800 rpm, 460 lb-ft torque @ 4000 rpm. Aluminum heads, 11.0:1 compression, 3x2-bbl carburetors (Rochester Tri-Power). Similar to L71 but with aluminum heads for weight reduction.

Bore X Stroke:

4.25 in x 3.76 in (107.95 mm x 95.25 mm)

Displacement:

427 cubic inches (7.0 Liters)

Valvetrain:

Overhead Valve (OHV), 16 valves (2 per cylinder), pushrod actuated.

Carburetion:

Single Holley 4-barrel (780 cfm on L36) or Rochester Tri-Power (3x2-barrel carburetors on L68, L71, L89), or High-performance Holley 4-barrel (850 cfm on L88).

Fuel Type:

Premium Unleaded Gasoline (minimum 91 octane recommended, higher for L88).

🔧 Transmission

Transmission Type:

Muncie M20 4-speed Manual (standard on some 427 models, particularly L36)

Optional Transmission 1:

Muncie M21 4-speed Close-Ratio Manual (standard on L71, L88, L89)

Optional Transmission 2:

Muncie M22 'Rock Crusher' 4-speed Heavy-Duty Manual (special order/racing option)

Optional Transmission 3:

Turbo-Hydramatic 400 (TH400) 3-speed Automatic

Clutch:

Single dry plate, heavy-duty clutch for manual transmissions.

Transmission Fluid Manual:

GL-4 Gear Oil (e.g., SAE 90)

Transmission Fluid Automatic:

Dexron III/Mercon compatible fluid (or original specification Dexron)

📐 Dimensions

Length:

175.1 inches (4448 mm)

Width:

69.2 inches (1758 mm)

Height Coupe:

47.8 inches (1214 mm)

Height Convertible:

46.2 inches (1173 mm)

Wheelbase:

98.0 inches (2489 mm)

Front Track:

54.5 inches (1384 mm)

Rear Track:

54.5 inches (1384 mm)

Curb Weight Coupe L36:

Approximately 3120 lbs (1415 kg)

Curb Weight Convertible L71:

Approximately 3180 lbs (1442 kg)

Curb Weight L88:

Approximately 3200 lbs (1451 kg)

Gross Vehicle Weight Rating:

Not explicitly rated for consumer use in the same way modern vehicles are, but designed for performance.

Cargo Volume:

Limited, particularly in convertible models. Approximately 10-12 cubic feet behind seats.

🛡️ Safety Features

Crash Test Ratings:

No formal government crash test ratings exist for vehicles of this era (pre-NHTSA establishment and standardized testing). Safety features were basic.

Active Safety Features:

Four-wheel hydraulic disc brakes (standard on 427), power steering (optional), limited-slip differential (optional).

Passive Safety Features:

Two-point lap belts, padded dashboard, energy-absorbing steering column, shatter-resistant safety glass.

💡 Technology Features

Infotainment System:

Basic AM/FM radio, optional AM/FM stereo with 8-track tape player. Typically analog gauges and controls.

Driver Assistance Features:

None in the modern sense. Primarily focused on the mechanical driving experience.

🔧 Maintenance

Oil Change Interval:

Recommended every 3,000 miles or 6 months, whichever comes first. Modern synthetic oils can extend this.

Tune Up Interval:

Spark plugs, points, and condenser replacement typically every 10,000-15,000 miles. Ignition timing checks recommended annually or every 10,000 miles.

Transmission Service:

Manual: Inspect fluid level annually. Automatic: Change fluid and filter every 24,000-30,000 miles or 24 months.

Coolant Change:

Every 2 years or 30,000 miles using a suitable ethylene glycol-based coolant.

Engine Oil:

SAE 10W-30 or 10W-40 for general use. SAE 20W-50 recommended for high-performance use or hot climates. API Service Category SF or SG (or equivalent).

Coolant:

50/50 mix of ethylene glycol antifreeze and distilled water.

Brake Fluid:

DOT 3 or DOT 4 Heavy Duty Hydraulic Brake Fluid.

Power Steering Fluid:

Dexron III/Mercon compatible automatic transmission fluid or specific power steering fluid.

Body Corrosion:

Fiberglass construction is resistant to rust, but steel subframes, chassis components, and door/window frames can be susceptible to corrosion.

Engine Cooling:

High-performance 427 engines can run hot. Ensuring the cooling system (radiator, fan, water pump, thermostat) is in optimal condition is crucial.

Carburetor Issues:

Tri-Power and large Holley carburetors can be finicky and require proper tuning. Vacuum leaks are common.

Rear Axle Leaks:

Positraction units can sometimes develop leaks at the axle seals or pinion seal.

Electrical Gremlins:

Aging wiring harnesses, connectors, and switches can lead to intermittent electrical problems, especially in lighting and gauges.

📚 Vehicle History

Chevrolet Heritage:

Chevrolet, established in 1911, has a long history of producing accessible and performance-oriented vehicles. The Corvette, introduced in 1953, has been Chevrolet's flagship sports car and a symbol of American automotive engineering prowess.

C3 Generation Intro:

The C3 generation, introduced for the 1968 model year, marked a significant styling departure from the C2 generation. It featured a radical new 'Mako Shark' inspired body design with flowing lines and a prominent fender bulge.

427 Introduction:

The 427 cubic inch engine was first introduced in the 1966 Corvette. For 1968, it became the dominant engine offering, with the '427' designation becoming a specific model trim due to the engine's prominence and power.

1968 Updates:

1968 was the inaugural year for the C3 Corvette. Key features included the new body style, standard side pipes (on most 427s), and the introduction of the L88 as a potent, albeit specialized, option.

Production Years:

C3 generation: 1968-1982. 1968 model year production: 28,566 Corvettes total.

1968 427 Production:

While exact figures vary by specific 427 engine RPO, the 427 engine option accounted for a significant portion of 1968 Corvettes. The L71 was the most common 427 engine.

Manufacturing Location:

St. Louis, Missouri, USA

🏆 Awards & Recognition

Automotive Icon:

The 1968 Corvette 427 is widely regarded as a classic American muscle car and a significant milestone in sports car history. It's a highly sought-after collector car.

Collectible Status:

Consistently ranked among the top collector cars, particularly L88 and L71 variants. High resale values in good condition.