How to Identify an L88 Chevy Engine

by Floyd Drake III
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The L88 427 c.i.d. engine is one of the most powerful Chevrolet big-block engines ever produced, and it was only available for a short time. The engine is most famously tied to the L88 Corvette from 1967 to 1969, and only 216 L88 Corvettes were manufactured during those years. The L88 Corvette was designed to be race-ready right out of the showroom, with over 550 horsepower, and its engine is now highly sought after.

Step 1

Identify the Corvette as an L88. The L88 is very rare and fetches upward of $100,000, Remember, there were only 216 manufactured and the 427 L88 engine was only used in these Corvettes. Because of their value, many Corvettes from 1967 through 1969 have been falsely labeled as L88s, so comparing different engine codes is the only reliable way to identify the L88 427.

Step 2

Locate the engine ID number on the forward passenger side of the engine block on a machined pad by the front of the cylinder head and timing cover. Remove the alternator if necessary to read the numbers.

Step 3

Decode the engine ID number. Chevrolet's coding system is easily deciphered and you will need to compare the number with a Chevrolet listing to determine the engine model. The last two or three letters at the end of the code will identify the engine block, the first five digits represent manufacturing plant and date.

Step 4

Compare the last two or three letters of the Chevrolet engine ID to a code listing. The following two-letter codes most likely identify the 427 L88: IT, IU, JA, JE, LP, LR, LT, LX, ME and LW. This listing is not definitive; confirm the code with the Chevy list.

Step 5

Remove the intake manifold. The date-code is located underneath the manifold and should read between 1967 and 1969 to be an L88 aluminum manifold. Next, find the cylinder head casting number. It is located on the driver's side, stamped between the second to last two valves toward the windshield. According to Corvette Action Center, this code should read either 3919842 or 3946074. There may be other L88 casting numbers, so a Chevrolet casting number list should be consulted.

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