How do I Check a GM Engine Block Code?

by Justin Cupler
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Every General Motors engine has several stampings on it. There is a date stamp and a casting stamp. The casting stamp is commonly referred to as the block code. This code identifies the size of the engine. Given that many of the blocks that GM produces are used for different engine sizes, this block stamping is very important for visual identification. Checking this block code is relatively easy; you just need to know what steps to take to locate it.

Step 1

Open the hood of your vehicle.

Step 2

Locate the block number. It is a seven-digit number on the rear driver's side of the engine. It will be just above the bell housing of the transmission. Use the flashlight if needed.

Step 3

Spray the de-greaser on the number and scrub it with the brush if it is covered with grease and unreadable.

Step 4

Make a note of the number, dues to the vast number of codes produced please refer to the resource to decode the block code. Unlike a vehicle identification number or an engine ID, a block code does not break down into a true meaning; it just refers to the make and model it was attached to from the factory.

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