How to Identify What Chevy Engine I Have

by Gary Powl
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Vehicle do-it-yourselfers need to know what engine they're working on before they head to the auto parts store to buy oil filters, fan belts, a carburetor or just about any other part. Figuring out what engine powers your Chevrolet is usually not difficult for anyone capable of raising the hood, especially on vehicles that have all the original equipment. Challenges arise with older or modified vehicles in which the engine may have been replaced. Identifying those engines may require looking for a code stamped on the engine and then finding out what it means.

Step 1

If it is available, check the user manual. It will specify the vehicle's engine options and include maintenance information.

Step 2

Open the hood. Identifying the engine, or confirming information from a user manual, is often as simple as looking at numbers prominently displayed on a valve cover or air intake.

Step 3

If necessary, look for the engine ID number. Chevrolet marks its engines with codes that specify when and where the engine was made, its size and its horsepower.

The code stamp is prominently placed. On straight six-cylinder engines, the code is stamped on a machined pad on the engine block's passenger side, behind the distributor. On V8s, the code is stamped on a machined pad at the front of the engine, on the passenger side. The alternator might conceal it.

Step 4

Interpret the code. There are too many letter combinations to list here, so you'll have to do a little searching online or consult a Chevy technical manual to make the final identification.

The code has seven characters for engines through the 1969 model year, eight characters on engines for 1970 and later. The first five characters for all years indicate the assembly plant and date of manufacture.

For Chevys made in 1969 or before, the code's sixth and seventh characters identify the engine and horsepower. For example, if the sixth and seventh characters for a 1967 Impala read "HA," the engine is a 327 V8 with 275 horsepower.

For later models, the sixth character identifies the type of vehicle (car or truck), the seventh and eighth characters identify the engine. For example, if the last two characters for a 1978 Camaro are "HR," the engine is a 350 V8 with 170 horsepower.

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