The eighth character in the Vehicle Identification Number (VIN) identifies the engine. Adhesive-backed labels attached to the engine, laser etching or stampings on the engine block indicate the engine unit number/date code. All engines are stamped with a VIN derivative. For added information on VIN derivative, refer to VIN Derivative .

The primary location (1) of the VIN derivative for the 3100 LG8 engine is above the starter motor on the engine block.

The primary location (1) and the secondary location (2) for the Engine ID for the 3100 LG8 engine on top of the RH rocker arm cover or front of RH oil pan rail.