Here we teach you how to read GM engine identification numbers, VIN numbers, and GM engine block casting number on all kind of GM cars. This information is useful to identify the manufactured year of an engine, where it was manufactured, product ID of an engine, as well as the engine capacity.

It makes things easier when you have known what kind of engine is running in your car especially when looking for new spare parts. Engine number or the VIN code is usually stamped on engine block, above the oil filter, somewhere on the block pad, or on somewhere around the transmission flange.

Chevrolet engine identification numbers (VIN)

Here we take a 1960s Chevrolet Camaro as an example:
1st digit: GM Line number: Chevrolet = 1.
2nd digit: Series number: Camaro = 2
3rd digit: Model/Engine number:
3 = 6-cylinder (1967-69 with standard interior) , 4 = V8 (1967-69 with standard interior)
5 = 6 cylinder (1967 – 69 with custom interior) , 6 = V8 (1967 – 69 with custom interior)
4th & 5th digit: Body Type Number:
37 = Sport Coupe (1967-69) 67 = Convertible (1967-69) 87 = Sport Coupe (1970-71)
6th digit: Last digit of model year:
7 = 1967, 8 = 1968, 9 = 1969, 0 = 1970, 1 = 1971
7th digit: Letter indicating assembly plant
L = Van Nuys, California, N = Norwood, Ohio
8th through 12th digits: Sequential production number starting with 100001.

In this case, the vehicle identification numbers (VIN) on a 1969 Chevrolet Camaro sport coupe V8 engine will be: 126379N100001.

General GM engine identification numbers

In recent years, GM has changed the VIN numbers to 17 digits. Here we decode the engine VIN numbers on most of the GM cars. For example, VIN 1G6DM57N030127718, where:

1G6 = Cadillac
DM = Cadillac
CTS 5 = Four door sedan
7 = Four plus rear side airbags
N = V6
0 = Check digit
3 = 1993
127718 = Sequential number