How to Identify a Chevy 400 Small Blockby Floyd Drake III
The 1970s were a tough decade for performance engines, with rising fuel prices and emissions regulations. It seemed that the muscle-car era was over. In 1970, Chevrolet introduced the 400-cubic-inch small-block engine into this environment, offering it for truck and large passenger car use. Although there were no high-performance editions of the 400, it is currently popular to rebuild and customize the 400 for high-performance applications, partially due to its availability and price. The Chevrolet 400 was produced from 1970 to 1980, and identifying it is a matter of locating and referencing the engine code suffix.
Open the hood and view the engine from the front on the passenger side.
Look for the engine code. According to the Chevy-Camaro website, the code is located on a machined pad directly forward of the passenger-side cylinder head, on the front of the engine block. A sample code reads "F0114CSB," with the first position designating the assembly plant, the second indicating the month, and the third marking the day of the month. The following letters -- CSB -- are the suffix that will identify the engine when referenced to a Chevrolet suffix listing.
Reference the engine code to a Chevrolet listing, similar to the one found on the 73-87.com website. When matched to this listing, the suffix code "CSB" is identified as a 1973 400-cubic-inch engine with 175 horsepower, originally installed in a Chevy Caprice.