1968 Corvette Front

1968 Corvette Performance & Specifications

Powertrain, Steering, Brakes, Dimensions, & Suspension

Last updated:

The arrival of the 1968 Corvette occurred at a time when the world, much like the Corvette itself, was struggling to find an identity of its own amidst political, social, and financial turbulence.

For its own part, General  Motors had recognized that skyrocketing gas prices and performance-car insurance premiums coupled with spiraling inflation made purchasing and owning a Corvette increasingly expensive for future consumers.

Read More: 1968 Chevrolet Corvette Research Center.

1968 Corvette Specifications

MODEL: 1968 Chevrolet Corvette
BODY STYLE: Two-door convertible/coupe, front engine, rear wheel drive
MANUFACTURING LOCATION: St. Louis, Missouri
CONSTRUCTION: Uni Construction: fiberglass reinforced plastic (FRP or “fiberglass”) body, backboned by a steel cage outlining the passenger compartment. Principal members – underbody, front and rear end assemblies, dash panel and hinge pillars are bonded, riveted, or bolted together and to each other. The Hood is plastic with bonded plastic reinforcement. Coupe: two removable roof panels and a removable rear window. Frame: all welded, full length, ladder construction with 5 crossmembers. Side Rails and intermediate cross members box section; front crossmember box girder section. Eight body-mounting points.
VEHICLE NUMBERS (VIN): 194378S400001 – 194378S428566
ENGINE SUFFIX: HE: 327 CUBIC INCH, 300 HP, MANUAL TRANS
HO: 327 CUBIC INCH, 300 HP, AUTOMATIC TRANS
HP: 327 CUBIC INCH, 350 HP, MANUAL TRANS, AIR CONDITION, POWER STEERING
HT: 327 CUBIC INCH, 350 HP, MANUAL TRANS
IL: 427 CUBIC INCH, 390 HP, MANUAL TRANS
IM: 427 CUBIC INCH, 400 HP, MANUAL TRANS
IO: 427 CUBIC INCH, 400 HP, AUTOMATIC TRANS
IR: 427 CUBIC INCH, 435 HP, MANUAL TRANS
IT: 427 CUBIC INCH, 430 HP (L88), MANUAL TRANS, ALUMINUM HEADS
IU: 427 CUBIC INCH, 435 HP, MANUAL TRANS, ALUMINUM HEADS
ENGINE BLOCK NUMBER: 3914678, 327 CUBIC INCH, 327 CUBIC INCH, 300 HP, 350HP
3916321, 427 CUBIC INCH, 390HP, 400HP, 430HP, 435HP
3935439, 427 CUBIC INCH, 390HP, 400HP, 430HP, 435HP
HEAD NUMBER: 3917215, 427 CUBIC INCH, 390HP, 400HP
3917291, 327 CUBIC INCH, 300HP, 350HP
3917292, 327 CUBIC INCH, 350HP
3919840, 427 CUBIC INCH, 435HP, IRON HEAD
3919842, 427 CUBIC INCH, 430HP, 435HP, ALUMINUM HEAD
CARBURETOR NUMBERS: ROCHESTER Q-jet #7028207: 327 CUBIC INCH, 300HP, MANUAL TRANS
ROCHESTER Q-jet #7028208: 327 CUBIC INCH, 300HP, AUTO TRANS
ROCHESTER Q-jet #7028209: 427 CUBIC INCH, 390HP, MANUAL TRANS
ROCHESTER Q-jet #7028216: 427 CUBIC INCH, 390HP, AUTO TRANS
ROCHESTER Q-jet #7028219: 327 CUBIC INCH, 350HP, MANUAL TRANS
HOLLEY R3659A #3902353: 427 CUBIC INCH, 400HP, 435HP
HOLLEY R4054A #3925519: 427 CUBIC INCH, 430HP (L88)
HOLLEY R4055A #3925517: 427 CUBIC INCH, 400HP, 435HP
HOLLEY R4055-1A #3940929: 427 CUBIC INCH, 400HP, 435HP
HOLLEY R4056A #3902516: 427 CUBIC INCH, 400HP, AUTOMATIC
DISTRIBUTOR NUMBER: 1111194: 327 CUBIC INCH, 300HP
1111293: 427 CUBIC INCH, 390HP, 400HP
1111294: 427 CUBIC INCH, 390HP, 400HP, TRANSISTOR IGNITION
1111295: 427 CUBIC INCH, 430HP, TRANSISTOR IGNITION
1111296: 427 CUBIC INCH, 435HP, TRANSISTOR IGNITION
1111438: 327 CUBIC INCH, 350HP
1111441: 327 CUBIC INCH, 350HP, TRANSISTOR IGNITION
1111475: 327 CUBIC INCH, 350HP, TRANSISTOR IGNITION
1111477: 327 CUBIC INCH, 350HP
ALTERNATOR NUMBER: 1100693: 300HP, 350HP, 390HP, 400HP
1100696: 350HP, 390HP, 400HP, 430HP, 435HP, TRANSISTOR IGNITION
1100750: ALL ENGINES WITH AIR CONDITIONING
AXLE IDENTIFICATION NUMBER AK: 3.36:1 RATIO, 3-SPEED, 4-SPEED TRANSMISSION
AS: 3.70:1 RATIO, 4-SPEED TRANSMISSION
POSITRACTION AXLE:
AL: 3.08:1 RATIO, 3-SPEED, 4-SPEED, & TURBO HYDRA-MATIC
AM: 3.36:1 RATIO, 3-SPEED, 4-SPEED TRANSMISSION
AN: 3.55:1 RATIO, 4-SPEED TRANSMISSION
AO: 3.70:1 RATIO, 4-SPEED TRANSMISSION
AP: 4.11:1 RATIO, 4-SPEED TRANSMISSION
AY: 2.73:1 RATIO, TURBO HYDRA-MATIC TRANSMISSION
PRODUCTION ENDING VEHICLE: SEP. 1967: 400905, OCT. 1967: 403410, NOV. 1967: 405682, DEC. 1967:407922, JAN. 1968: 410386, FEB. 1968: 412647, MAR. 1968: 415000, APR. 1968: 417676, MAY 1968: 420928, JUN. 1968: 423978, AUG. 1968: 428566

1968 Corvette Powertrain Specifications

Order Code Standard L79 L36
Manufacturing Location Flint, Michigan Flint, Michigan Flint, Michigan
Type 90 degree V, Valve-In-Head 90 degree V, Valve-In-Head 90 degree V, Valve-In-Head
Cylinders 8 8 8
Displacement (cid) 327 327 427
Fuel Induction System Carburetor Carburetor Carburetor
Horsepower 300 @ 5,000 350 @ 5,800 390 @ 5,400
Torque 360 @ 3,200 360 @ 3,600 460 @ 3,600
Bore x Stroke (in.) 4.00 x 3.26 4.00 x 3.26 4.251 x 3.76
Compression Ratio 10.0:1 11.0:1 10.25:1
Firing Order 1-8-4-3-6-5-7-2 1-8-4-3-6-5-7-2 1-8-4-3-6-5-7-2
Cylinder Number System (Left) 1-3-5-7 1-3-5-7 1-3-5-7
Cylinder Number System (Right) 2-4-6-8 2-4-6-8 2-4-6-8
Recommended Fuel Premium Premium Premium
Order Code L68 L71 L88
Manufacturing Location Flint, Michigan Flint, Michigan Flint, Michigan
Type 90 degree V, Valve-In-Head 90 degree V, Valve-In-Head 90 degree V, Valve-In-Head
Cylinders 8 8 8
Displacement (cid) 427 427 427
Fuel Induction System Carburetor Carburetor Carburetor
Horsepower 400 @ 5,400 435 @ 5,800 430 @ 5,200
Torque 400 @ 3,600 460 @ 4,000 485 @ 4,000
Bore x Stroke (in.) 4.251 x 3.76 4.251 x 3.76 4.251 x 3.76
Compression Ratio 10.25:1 11.0:1 12.5:1
Firing Order 1-8-4-3-6-5-7-2 1-8-4-3-6-5-7-2 1-8-4-3-6-5-7-2
Cylinder Number System (Left) 1-3-5-7 1-3-5-7 1-3-5-7
Cylinder Number System (Right) 2-4-6-8 2-4-6-8 2-4-6-8
Recommended Fuel Premium Premium 103 RON Minimum

1968 Corvette Manual Transmission/Gear Ratios

Manual Transmission

Gear Ratios  3-Speed
4-Speed (RPO M20)
4-Speed Close Ratio (RPO M21)
4-Speed Heavy Duty (RPO M22)
1st Gear:
2.54:1
2.52:1
2.20:1
2.20:1
2nd Gear:
1.50:1
1.88:1
1.64:1
1.64:1
3rd Gear:
1.00:1
1.46:1
1.27:1
1.27:1
4th Gear:
N/A
1.00:1
1.00:1
1.00:1
Reverse:
2.63:1
2.59:1
2.26:1
2.26:1

Clutch

Clutch Stats
Type Three, Multi-disk
Spring Pressure (lbs) 2100 – 2300 Std. (2300 – 2600 with RPO L79) (2450 – 2750 with RPO L36 and L68) (2600 – 2800 with RPO L71)
Lining area (sq. in.) 101.54 Standard and L79 (123.70 for RPO L36, L68, and L71)

Turbo Hydra-Matic Automatic Transmission RPO M40/ Gear Ratios

Gear Drive L2 L1 Reverse
1st Gear 2.48:1 2.48:1 2.48:1 N/A
2nd Gear 1.48:1 1.48:1 N/A N/A
3rd Gear 1.00:1 N/A N/A N/A
Reverse N/A N/A N/A 2.08

 


1968 Corvette Wheels, Suspension & Brakes

Suspension – Front

Type and Description: Independent, SLA type, coil springs with center mounted shock absorbers, spherical joint steering knuckle pivots.

Front Coil Springs
Make & Type Right-hand Helix Variable rate
Material Steel Alloy
Part Number 3931823, 3931825
Spring Rate (lb. per in.) 250 (284)
Rate at Wheel (lb. per in.)
Design Load at Spring 9.99 in. @ 1395 lbs. (9.99 in. @ 1540 lbs.
Front Stabilizer Bar
Type Link
Material Hot rolled steel
Diameter .750 with 327ci engine, .9375 with 427ci engine

Suspension – Back

Type and Description: Full Independent rear suspension with frame-anchored differential unit. Position of each wheel established by three links: tubular axle drive shafts, transverse strut rods, torque control arms. Vertical suspension loads taken by transverse leaf springs. Built-in camber adjustment at strut rod inner ends.
Rear Leaf Springs
Number of Leaves 9
Material Chrome carbon steel
Length, width, height 46.36 x 2.25 x 2.121
Rear Shock Absorbers:
Type Direct, double-acting, hydraulic
Piston Diameter 1.00
Rear Strut
Material Forged Steel
Diameter 0.75

Brakes

Brake Specs
Type:
– Standard Caliper Disk – 4 Wheel Hydraulic
– J50 Delco-Moraine Vacuum Assisted Powered Brakes
Drum diameter, front (in.): 11.75 x 1.25
Drum diameter, rear (in.): 11.75 x 1.25
Swept Drum Area Effective area: 461.2

Wheels & Tires

Wheels & Tires Specs
Wheel Type:
– Standard Short spoke spider, welded steel
– P48 Ribbed integral casting, aluminum, quick take-off
Wheels, size:
– Standard 15″ x 7.00
Tire, size:
– Standard F70 x 15 — 4 PR. 2-Ply Tubeless Rayon
– PT6 F70 x 15 — 4 PR, 2-Ply Red Stripe Nylon
– PT7 F70 x 15 — 4 PR, 2-Ply White Stripe Nylon
Inflation (cold)
– Front 24 lbs.
– Rear 24 lbs.

Steering

Steering Specs
Type Semi-reversible, recirculating ball and nut steering gear with three-inch axial column adjustment; two-location steering arm-tie rod connection for street and fast ratio. Telescoping shaft steering available optionally.
Make Saginaw
Ratio (Gear) 16.0:1
Wheel Diameter (in.) 16
Turns, Stop to Stop
– Standard 3.4
– Power 2.92
Turning Diameter 37 ft. (outside front), 39 ft. (outside front)

1968 C3 Corvette

1968 Corvette Exterior Dimensions

Hard Top Dimensions

1968 Corvette Dimensions - Coupe

Exterior Dimensions (Hardtop) Interior Dimensions (Hardtop)
Wheelbase: 98.0 Inches Headroom: 37.1 Inches
Overall Length: 182.1 Inches Shoulder Room: 46.9 Inches
Total Body Width: 69.2 Inches Hip Room: 48.8 Inches
Overall Height: 47.9 Inches Leg Room: 43.0 Inches
Front Track Width: 58.3 Inches
Rear Track Width: 59.0 Inches
Min. Ground Clearance 4.9 Inches

Soft Top Dimensions

1968 Corvette Dimensions - Soft Top

Exterior Dimensions (Soft Top) Interior Dimensions (Soft Top)
Wheelbase: 98.0 Inches Headroom: 37.1 Inches
Overall Length: 182.1 Inches Shoulder Room: 46.9 Inches
Total Body Width: 69.2 Inches Hip Room: 48.8 Inches
Overall Height: 47.9 Inches Leg Room: 43.0 Inches
Front Track Width: 58.3 Inches
Rear Track Width: 59.0 Inches
Min. Ground Clearance 4.9 Inches

Coupe Dimensions

1968 Corvette Dimensions - Hard Top

Exterior Dimensions (Coupe) Interior Dimensions (Coupe)
Wheelbase: 98.0 Inches Headroom: 36.2 Inches
Overall Length: 182.1 Inches Shoulder Room: 46.9 Inches
Total Body Width: 69.6 Inches Hip Room: 48.8 Inches
Overall Height: 47.8 Inches Leg Room: 43.0 Inches
Front Track Width: 58.3 Inches
Rear Track Width: 59.0 Inches
Min. Ground Clearance 4.9 Inches

Capacities

Capacities
Passenger Capacity 2 – Driver & Passenger
Curb Weight (lbs) 3,220
– Convertible 3,268
– Convertible (with hardtop) 3,210
Interior Passenger Volume (cu. ft)
Interior Trunk Volume (cu. ft) 20
Fuel Capacity (gallons): 20
Coolant capacity without heater (qts.) 21.0 with L36, L68, and L71
Battery: 12 volt, 62AH

1968 C3 Corvette

1968 Corvette Performance Results

3-Speed Transmission
Standard
L79 L36 L68 L71
Performance weight (lbs.)
3510
N/A
N/A
N/A
N/A
Pounds/gross horsepower
11.70
N/A
N/A
N/A
N/A
Pounds/cu.in. piston displacement
10.37
N/A
N/A
N/A
N/A
Gross horsepower/cu.in. displacement
.917
N/A
N/A
N/A
N/A
Power displacement (cu.ft./mile)
243.52
N/A
N/A
N/A
N/A
Displacement factor (cu.ft./mile)
138.76
N/A
N/A
N/A
N/A
0 – 60 mph (seconds)
N/A
N/A
N/A
N/A
Top Speed (mph)
N/A
N/A
N/A
N/A
4-Speed Transmission
Standard
L79 L36 L68 L71
Performance weight (lbs.)
3510
3516
3682
3686
3653
Pounds/gross horsepower
11.70
10.05
9.44
9.21
8.40
Pounds/cu.in. piston displacement
10.37
10.75
8.62
8.63
8.55
Gross horsepower/cu.in. displacement
.917
1.070
.913
937
1.019
Power displacement (cu.ft./mile)
243.52
243.52
291.50
291.50
335.98
Displacement factor (cu.ft./mile)
139.00
138.52
158.34
158.16
184.00
0 – 60 mph (seconds)
8.6
7.1
N/A
6.1
6.3
Top Speed (mph)
128
117
N/A
145.7
160

 

3-Speed Transmission
Standard
L79 L36 L68 L71
Performance weight (lbs.)
3457
N/A
3632
9.08
N/A
Pounds/gross horsepower
11.52
N/A
9.31
8.51
N/A
Pounds/cu.in. piston displacement
10.37
N/A
8.51
.937
N/A
Gross horsepower/cu.in. displacement
.917
N/A
.913
315.09
N/A
Power displacement (cu.ft./mile)
241.30
N/A
315.09
173.51
N/A
Displacement factor (cu.ft./mile)
139.64
N/A
173.51
N/A
0 – 60 mph (seconds)
N/A
N/A
Top Speed (mph)
N/A
N/A

1968 C3 Corvette