This relic may have the same basic engine, cylinder heads, frame and rearend that rolled off the assembly line, but the parts required to make it whole again are far too significant to consider it a “numbers matching” car. That was the way it was advertised on where we found this photo.

Terms are thrown around loosely in the automotive industry, especially by salesmen looking to unload a component or vehicle on others. “It is a numbers matching car,” or “It is a matching numbers engine,” they boast.

What do these numbers match and which parts get numbers? Do parts like windshield wiper arms (which have part numbers) and glove box light bulbs (which also have part numbers) get consideration or is it just reserved for major components? Which major components are involved in the “numbers matching” game?

The only reason these numbers have any relevance in the restoration industry is to help judges find errors in the restored builds. The Ring Brothers‘ Mike Ring once explained to us that “When you get into restorations, it’s about what you did wrong, Did you have the right date code on the lightbulb in the glovebox? It just about wore us out worrying about what was wrong.” Photo from

Historically the collector car groups have often used the term to mean numbers or codes that match the original components to a vehicle when it was new. The debate has always been, which components should be included to be considered 100-percent numbers matching and how to verify those numbers.

Take into consideration an OE built engine. Parts fail and need replaced over the years. After four or five decades, it is highly unlikely that the fuel pump, water pump, carburetor or even the exhaust manifold is the same. If a carburetor is replaced because of wear, and a like carburetor is installed, is it still a numbers matching engine?

We’ve heard of numerous builds where the chassis ID tag was removed from an original chassis that was unusable, and placed on a newer fabricated chassis. Does the data plate make that new chassis original? If not, what percentage of the chassis can be replaced before it is no longer considered original?

Does every major component on this engine have to be original to be a complete “numbers matching” engine assembly? Photo from

Where we draw the line is verification. It is so difficult to prove that numbers were not re-stamped into new components in order to command a higher price. Parts can also be re-cast with whatever marks or numbers a customer is willing to pay for on freshly cast components.

Think about it this way: Caitlyn Jenner has the same SSN as Bruce Jenner. Just because they have the same number, it doesn’t mean that the chassis is the same? Ok, that might be a stretch, but you get the point.

Same SSN but are the parts still OE stock or have there been modifications? Numbers matching chassis? Photo from

We tend to think that the lesson learned in “numbers matching” cars or engines is to not over value the importance or significance in numbers matching cars. Perhaps we should just enjoy the cars as they exist. And … we’re going to leave that right there.