It should be noted that this information pertains to Chevelles only. Other Chevrolet lines (Camaro, Nova, etc.) and their plants may differ. For example, a 1969 full size car with a 350 V8 from Van Nuys has been reported with the partial VIN on the oil filter boss and other Chevrolet models and/or plants may exhibit the same properties. 

Sample of Baltimore stamping on engine pad.

Sample of Framingham stamping on engine pad.

Kansas City, MO

Research indicates that the Atlanta & Kansas City plants used this alternate location for 396 engines. This is a partial VIN stamping from Kansas City.

Another Kansas City plant stamp.

Atlanta, GA

Atlanta 396 partial VIN stamping

Atlanta 396 partial VIN stamping.

Atlanta 396 partial VIN stamping.

Atlanta 396 partial VIN stamping.

Courtesy Greg Wilson