The Vehicle Identification Number (VIN) has similar information as the trim tag such as the model, year, and assembly plant. The differences are the last six numbers relating to the assembly plant sequence as opposed to the trim tag's Fisher Body sequence and the series will designate a 6-cyl (odd 3rd digit) or V8 (even 3rd digit).

A typical 1968 Chevelle VIN might read: 138377B164166 being an SS396 2-dr Sport Coupe assembled in Baltimore, MD.

First Character: Division of General Motors
1 - Chevrolet

Second and Third Character: Series Designation
31 - Chevelle 300, 6-cylinder
32 - Chevelle 300, 8-cylinder
33 - Chevelle 300 Deluxe, El Camino (Deluxe), 6-cylinder
34 - Chevelle 300 Deluxe, El Camino (Deluxe), 8-cylinder
35 - Malibu, El Camino (Custom), 6-cylinder
36 - Malibu, El Camino (Custom), 8-cylinder
37 - Concours, 6-cylinder
*38 - SS396, Concours,  8-cylinder

Fourth and Fifth Character: Body Style/Model
27 - 2-door coupe
35 - 4-door station wagon, 2 seats
36 - 4-door station wagon, 2 seats, dual tailgate
*37 - 2-door sport coupe
39 - 4-door sport sedan
67 - 2-door convertible
69 - 4-door sedan
80 - 2-door sedan pickup

Sixth Character: Year of Production
8 - 1968

Seventh Character:
Final Assembly Plant
A ~ Atlanta, Georgia
*B ~ Baltimore, Maryland
Z ~ Fremont, California
G ~ Framingham, Massachusetts
K ~ Kansas City, Missouri
1 ~ Oshawa, Ontario, Canada

Eighth through Thirteenth Characters: Sequential Production Number
The sequential starting number for the 1968 Chevelle was 100001 at all U.S. Chevelle assembly plants. Each assembly plant sequenced Chevelles of all series/models without regard to specific series/models. For example, if a series 13435 station wagon followed a 13667 Malibu convertible, the sequence number would be one unit higher for the wagon. It's also entirely possible to have the same sequence number from all five 1968 U.S. assembly plants with the only difference between the VINs being the plant code.

Production exceeded 100,000 units for the Baltimore plant sometime in May, and the Kansas City plant sometime in April so the VIN sequence for those respective time frames to the end of production would be 2nnnnn for each plant.