How to Identify a Chevy Engine by Numbers

You can identify a Chevy by the numbers on its engine block, recorded in an official Chevy engine block registry. The identification number consists of a seven-to-eight digit code. The prefix consists of five digits and explains the date and the location of the Chevy's manufacture. The suffix provides the size, model year, and the horsepower of the Chevy engine. The suffix can be either two digits or three digits.

Step 1

Locate the Chevy identification number on the engine block. Depending on the size of the engine, the location of the identification number will vary. Look for the identification number on the engine block. The identification numbers on a Chevy engine with a small block V-8 are adjacent to the cylinder heads on the passenger’s side, close to the front of the engine block. Look closely because the alternator blocks the identification number. The identification numbers on a Chevy big block V-8 engine are on the covering of the timing chain. Find the identification numbers of a V-6 on the distributor, which is on the passenger’s side of the engine.

Step 2

Decipher the Chevy engine identification number prefix. The identification number contains a combination of numbers and letters and is seven or eight characters. The prefix explains the location as well as the date of the Chevy engine's manufacture. For example, a Chevy engine with the identification number S1029CTY was manufactured in Saginaw (S) on September (10) the 29th (29).

Decipher the Chevy engine identification number suffix. The two-to-three character suffix tells the owner the displacement of the engine, the horsepower of the engine, and the year and model of the vehicle. Taking the example from above, CTY is the identification number suffix. CTY stands for a 1970 Camaro with a 396 c.i.d and 375 horsepower. Remember to always reference the online identification guide to ensure an exact match.