See Figures 1 and 2
The engine serial number consists of an engine series identification number, followed by a 6-digit production number. The location of this serial number varies slightly from one engine to another. On the K-series engines (3K-C), the number is stamped on the right side of the engine, below the spark plugs. On most other engines covered by this information, the serial number is stamped on the left side of the engine, behind the dipstick.