Chevrolet engine stamp codes inform mechanics where an engine was manufactured, when it was produced and what type of vehicle it was originally built for. Generally, the engine assembly date precedes the car build date by a few days.
Chevrolet engine stamp codes begin with a character that identifies one of seven different engine plant codes. This character indicates whether the engine was built in Flint, Michigan; St. Catherines, Ontario; Saginaw, Michigan; Tonawanda, New York or in GM's Mexico factory.
After the engine identification code, four digits represent the month and day of the engine's production. The first two digits represent the month and the next two digits represent the day. Following these characters, a three-character code indicates what type of vehicle the engine belongs to. Thousands of suffix codes exist, and they are not necessarily mutually exclusive. For example, the suffix code "CML" applies to one of four options, including a 1975 Chevrolet Camaro with 155 horsepower and a 1980 Chevrolet Z-28 with 190 horsepower. The suffix code for a 1970 396 Camaro with 375 horsepower is "CTY."
Nastyz28.com offers users access to a list of engine suffix codes for both small block and big block Chevrolet engines. This list is not a complete one, but it is very comprehensive and contains the majority of Chevrolet models.