GM Full-Size Trucks 1980-1987 Repair Guide



See Figures 1, 2 and 3

The Vehicle Identification Number (VIN) is on a plate attached to the left hand door pillar, or on the left top of the dashboard (visible through the windshield) on later models. The gross vehicle weight (GVW), or maximum safe total weight of the truck, cargo, and passengers, is also given on the plate.

Click image to see an enlarged view

Fig. Fig. 1: Vehicle identification plate


The VIN is on a plate attached to the upper left hand side of the instrument panel. The first letter indicates a Chevrolet (C) or GMC (T) vehicle. The second letter is the drive type, "C" for two wheel drive or "K" for four wheel drive. The third letter is the engine type. 1980 engine letter codes are as follows:

D: 250 Six
T: 292 Six
U: 305 V8
M: 350 V8 2 barrel
L: 350 V8 4 barrel
R: 400 V8
S: 454 V8
Z: 350 V8 Diesel

The first and the fourth digits in the VIN is the GVW range, 1 ( 1 /2 ton), 2 ( 3 /4 ton), 3 (1 ton) and 4 ( 1 /2 ton HD susp). The second number and fifth digit in the VIN designates the model or body style type, they are:

2: Chassis Cowl, Forward control Chassis
3: Chassis Cab
4: Cab and Pick Up Box or Hi-Cube Van
5: Chevy Van and Step Van
6: Sport Van and Suburban
7: Motor Home Chassis
8: Blazer

The fourth letter and sixth digit in the VIN designates the model year, " A " for 1980, for example. The fifth letter and seventh digit indicates the assembly plant where the truck was assembled.

A: GMAD Lakewood GA
B: GMAD Baltimore MD
F: Chevrolet Flint MI
J: GMAD Janesville WI
S: GMAD St. Louis MO
Z: GMAD Freemont CA
O: GM Truck Pontiac MI
1: GM of Canada Oshawa Ont.
3: Chevrolet Detroit MI
4: GM of Canada Scarborough OH
7: GMAD Lordstown OH

The last six numbers in the VIN number are the sequential serial number.


Beginning in 1981 a new 17 digit code is used. The interpretation is the same as previous years except that the engine code is the eighth digit. Additional engine codes include the F and H codes, 305 V8; P code, 350 V8; W code 454 V8; C and J codes, a Chevrolet built 379 cu. in. V8 diesel.

Click image to see an enlarged view

Fig. Fig. 2: 17-digit VIN, 1981 and later

Click image to see an enlarged view

Fig. Fig. 3: Engine Identification Codes by VIN Number 1981-1987