The head casting numbers for a Chevrolet engine are located on the middle of the cylinder head. The valve covers must be removed to find the numbers.
The casting numbers are located under the valve covers. Keep in mind that if you remove the valve covers, new gaskets may be needed. The numbers are located in an area that may be oily, so some cleaning may be needed to read the numbers. The numbers themselves indicate the year the head was cast, the size of the engine the heads were designed for in cubic inches, and the valve sizes.
Charts that interpret the casting numbers are available on several websites. OutInTheShop.com offers a chart that is available by clicking on the Chevrolet casting numbers link. After clicking, scroll down the find your number, or try using the search link at the top of the page. This information can be helpful if you're buying a car that has had an engine replaced. It's possible that an engine from a different year or an engine with different specifications was installed. One advantage of Chevrolet vehicles is that many of the parts are interchangeable. That can also lead to problems if an entire engine has been changed and later requires service. Checking the casting numbers can prevent purchasing the wrong parts or performing incorrect repairs.