Vehicle Identification Number Decoding 1969-1991

1969

The first letter is B. The second letter is the chassis type: C for two wheel drive, K for four wheel drive. The third letter is the engine: S for 6 cylinder, and E for V-8. The remainder of the VIN is numerical with the exception of the letter idetifying the assembly plant. The first number represents the load capacity: 1 for 1/2 ton. The 2nd and 3rd numbers indicate the cab to axle measurement: 07 meaning 42-47 inches. The 4th and 5th numbers indicate the body style: 14 for the Blazer utility body. The 6th number is the last digit of the model year: 9=1969. The next letter indicates the assembly plant. The remainder of the numbers are that vehicle's particular serial number.

1970-1971

The first letter represents the chassis type: C is two wheel drive, K is four wheel drive. The 2nd letter is the engine: S for 6 cylinder, E for V-8. The 1st number gives the load capacity: 1 for 1/2 ton. The 2nd number is the body style: 8 for Blazer/Jimmy utility body. The 3rd number is the last digit of the model year: 1=1971. The next letter indicates the assembly plant. The remainder of the numbers are that vehicle's particular serial number.

1972-1980

The first letter indicates the make: C for Chevrolet, T for GMC. The 2nd letter is the chassis type: C for two wheel drive, K for four wheel drive. The 3rd letter represents the engine: in 1972 it's S for 6 cylinder, E for V-8. For 1973-1980 the engine ID letters are:

ID Letter	Engine Description	Notes
Q	250 c.i. 6 cylinder	Through 1975
D	250 c.i. 6 cylinder	From 1976
U	305 c.i. V-8
X	307 c.i. V-8
V, M	350 c.i. 2 bbl V-8
Y, L	350 c.i. 4 bbl V-8
U	400 c.i. V-8	Through 1976
R	400 c.i. V-8	1977-1979

After the engine identification letter, the 1st number gives the load capacity: 1 for 1/2 ton. The 2nd number is the body style: 8 for Blazer/Jimmy utility body. The 3rd number is the last digit of the model year: 8=1978. The next letter indicates the assembly plant. The remainder of the numbers are that vehicle's particular serial number.

1981-1991

For these years, the new "world" style VIN consisted of 17 characters. The decoding is as follows... The first number indicated nation of origin: 1=U.S.A. 2=Canada. The next symbol is a letter: G for General Motors. The third symbol is a letter: C for truck. The fourth symbol is a letter: E for a GVWR of 6001-7000 lbs. and it also designates hydraulic brakes. The fifth symbol is a letter: K for Conventional cab, 4x4. The sixth symbol is a number: 1 for 1/2 ton. The seventh symbol is a number: 8 for Blazer. The eighth symbol is a letter identifying engine type and make. Please refer to the table below:

 
ID
Letter

Engine Type
Displacement in 
Cubic Inches (Litres)

The ninth symbol is a number: This is a check digit. The tenth symbol is a letter: B=1981, C=1982, D=1983, E=1984, F=1985, G=1986, H=1987, I=1988, K=1989, L=1990, M=1991. The eleventh symbol is a letter or number indicating the assembly plant: A=Lakewood, B=Baltimore, F=Flint, J=Janesville, S=St. Louis, V=Pontiac, 1=Oshawa, Canada, 3=Detroit, 4=Scarborough, Canada, 7=Lordstown. The last six digits are that truck's sequential serial number.