How to Identify a GM 454

by Floyd Drake III
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That early 1970s SS Chevelle rumbling at a red light is more than likely being powered by a GM Chevrolet 454 c.i.d. big-block. Although also offered as a large car and truck option, the 454 was most famously used in Camaro and Chevelle SS models from 1970 through 1973. The 454 option ended for passenger cars in 1976, but continued as late as 2000 for trucks and marine applications as the 7.4 Liter version. Being a bored-out 396 c.i.d. block, the 454 can be easily identified by comparing Chevrolet casting and ID numbers.

Step 1

Identify the year and model. Knowing the year of manufacture will give a general idea if the engine may be a 454 c.i.d. The models most likely to have the 454 are early 1970s Camaro and Chevelle SSs, Corvettes, Monte Carlos and Chevrolet/GM trucks. Look for any tags in the engine compartment or the trim tag located on the fire wall behind the master cylinder. These may identify the year and model.

Step 2

Look for decals on the engine. GM usually identified the 454 with decals, located on either the air cleaner or valve covers, but they may have been removed or worn off.

Step 3

Locate the engine ID number located at the front of the engine block on the passenger side. It will be in front, near the timing chain cover and the cylinder head. It is a mixed-digit number with seven to eight characters, similar to C0622CPD.

Step 4

Decode the ID number. The first letter represents the engine manufacturing plant, followed by four numbers for the month and day of manufacture. The next three letters are the engine code which tells the year, amount of horsepower and vehicle model the engine was originally manufactured for. The engine ID number must be cross-referenced with a GM listing. Chevy-Camaro has a complete listing for all 454 c.i.d engines.

Step 5

Verify the casting numbers from either the cylinder head, intake manifold or crankshaft. The easiest two are the intake manifold, located in front of the carburetor mount, or the cylinder head, located on the right-hand side, while looking at it from the side of the vehicle. After removing the valve cover, the head casting number will be on the upper valley between two valves. Both numbers are usually seven digits long and need to be compared to a GM casting number list.

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