We get a number of inquiries regarding casting numbers, engine build
dates and engine assembly/suffix codes. Many folks want to know where to
look for these Chevy engine casting numbers and codes on blocks and cylinder
heads so we decided to put these
pages with photos together to help you find them. Most are easy to find once you know
Keep in mind that some of the numbers or letters can be difficult to read. A "6" can look like an "8" or an "8" can look like a "3". A upper case letter "I" can look like the numeral "1" and visa versa. Some times part of the number may be missing. A "T" can have the top horizontal part of the letter missing making it look like the upper case letter "I" or a lower case letter "l".
Remember that you have to look at ALL of the numbers, features and parts characteristics to figure out what it is you are looking at. A number of the casting dates refer only to the year of the decade so you will have to see which other features the part has to determine which decade it was made in. Some casting dates do have the year and the decade indicated, making it easier.
We are always looking for new Chevy engine castings numbers. If you have some information you want to share with us and our visitors, send us an email with the data. Right now we are limiting our listings to Chevy V-8 blocks, cranks and heads. As new castings are released on late models keep your eyes open for the new numbers. Thanks!
The diagram above shows where each of the casting identifiers is located on the engine. (1) shows the location of the HEAD CASTING NUMBERS and the HEAD CASTING DATE located under the valve covers, in the rocker arm valley. (2) shows the position of the BLOCK CASTING DATE on the rear ledge of the block near the bell housing mounting surface. If you have an early big block or a late model smallblock, the BLOCK CASTING DATE may be on the passenger side of the engine block, (see 2A), instead of the rear ledge of the block. Some smallblock blocks may also have the BLOCK CASTING DATE on the driver's side of the block. (3) indicates the position of the BLOCK CASTING NUMBER. Later blocks may also have the size of the engine displacement in liters listed at (3). (4) indicates the position of the ENGINE ASSEMBLY DATE/SUFFIX CODE and partial VIN code information on the front of the block. (5) on the rear flange of the block, on the drivers side near the oil filter pad, is an alternate block location for some VIN codes. (6) indicates the sides of the block where some blocks may have the size of the motor indicated in cubic inches or in liters. The last three numbers of the block casting number may also be repeated in this location.
There are three block casting number types to look for: the block CASTING NUMBER, the block CASTING DATE and the ENGINE ASSEMBLY DATE/SUFFIX CODE.
The block casting date indicates when the block itself was cast in the foundry. This date does not indicate when the motor was assembled and then later placed into the vehicle at the factory. The block casting date is usually found on the rear ledge of the block on the passenger side, but some later model blocks have the casting date on the driver's side of the rear ledge. Some of the early big blocks made in the Sixties have the block casting date located on the passenger side of the block near the freeze plug holes. On these, if the early big block is in the car you will have to get under the motor to see the casting date. Do it while the car is on a lift. The casting dates look something like this "E 12 7". The "E" stands for the month of the year with "A" being the month of January, "B" being the month of February and so on thru the letters to December. In this case the "E" stands for the month of May, the fifth month of the year and the fifth letter of the alphabet. The "12" stands for the 12th day of the month. The "7" is the year of the decade. Now unfortunately this could be '57, '67, '77, '87 or '97 depending on which part you are looking at. Some casting dates have both the year of the decade and the decade itself. They look like this "E 12 77", meaning May 12, 1977. The fun starts when you have a casting date from the first nine days of the month that look like this "D 2 6". Does that stand for April 2,1966 or does it stand for April 26th and the year is missing or hard to see? You have to look closely and carefully to be sure.