GM Engine Block Casting Numbers Hold a Lot of Information

When determining the authenticity of a GM engine nothing is more important then the casting number, the casting number can't be re-stamped like an RPO code can, and for the engine to be authentic the two codes must match.

For this article I will concentrate on the GM engine block casting number, this number will hive you vital information like horsepower; CID; rather it's a 2 or 4 blot main, and other information it's a number that you must familiarize yourself with.

On most GM blocks it can be found on the top back of the block where the transmission mounts to the engine, you may need to clean it off to read it, they often get covered with grease, this tool will help you decode your GM casting number Casting Decoder.

There are books that you can get such as the by the number series of books published by Colvin, and available at Barnes & Nobel book stores, these books have helped me identify a lot of different cars, and engines for people, they are essential reading.

For the person who collects GM cars, or wants to start collecting them you need to know what these numbers are telling you, for a collector the most important thing is authenticity of the car, you cannot afford to take any chances here at all.

All of the numbers must match perfectly on the car or you will lose in the end, as I have said so many times in the past, study; learn; and know whats going on before you start collecting cars for investment purposes.

A casting number is a raised number, not a stamped number making it impossible to re-stamp it can tell you a lot about the engine in you can, but it only tells part of the story, it has to match up to the vin code, and the RPO code to tell the whole story.

The casting number in combination with the RPO code can tell you the date the engine was built; and the factory that it was built in, and if it belongs in the car that it's in; if you know how to decode these two numbers you can learn a wealth of information.

It is without a doubt essential for you to know these two numbers if your to learn if your engine is the authentic piece of hardware that came in your car; if your buying this car for an investment you must know these things, it's not a maybe, it's a must.