Engine Identification

Fig 1: Locating VIN On Left & Right Rear Side Of Engine Block

Courtesy of GENERAL MOTORS CORP.

The Vehicle Identification Number (VIN) Derivative is located on the left side rear of the engine block (1) or on the right side rear (2) and typically is a nine digit number stamped or laser etched onto the engine at the vehicle assembly plant.
- The first digit identifies the division.
- The second digit identifies the model year.
- The third digit identifies the assembly plant.
- The fourth through ninth digits are the last six digits of the Vehicle Identification Number (VIN).
Engines built at the Tonawanda engine plant have the engine identification number located at the right front top of the engine block.
- The first digit (1) is the source code.
- The second and third digits (2) are the month of build.
- The forth and fifth digits (3) are the date of build.
- The sixth, seventh, and eighth digits (4) are the broadcast code.
  
  Fig 2: Locating VIN On Right Front Top Of Engine Block (Tonawanda Plant)
  Courtesy of GENERAL MOTORS CORP.
Engines built at the Romulus engine plant have the engine identification number located at the right front top of the engine block.
- The first digit (1) is the source code.
- The second and third digits (2) are the month of build.
- The fourth digit (3) is the hour of the build.
- The fifth and sixth digits (4) are the date of build.

Fig 3: Locating VIN On Right Front Top Of Engine Block (Romulus Plant)

Courtesy of GENERAL MOTORS CORP.