The Corvette Action Center is a great repository of information. This article on purchasing a pre-owned Corvette gives a great overview of the subject.
Buying your first Corvette can be a difficult task if you’re not sure what to look for. You’ve heard all the terms ("matching numbers", "body-off restoration", "frame-off restoration" etc), but you’re not sure what they mean. Our goal here is to provide you with a little bit of knowledge before you go into the Corvette buying world and to supply you with a handy check list of items that you may want to check out the Corvette that you’re interested in purchasing. Depending on options, some of the items on the list may or may not apply to the particular Vette that you’re looking at. Hopefully, we’ve compiled a fairly broad enough array of items to look at that will cover just about all Corvette model years.
Below, are a few of those definitions defined and we’ve added the checklist for you to take a look at.
Matching-Numbers: By far, this is probably the most commonly used term you will ever see when it comes to buying a Corvette. Many owners claim that their Corvettes are matching numbers, but many owners fail to have a good understanding of what the term truly means.
Most parts on a Corvette come with serial numbers and date codes. Often the serial number of the part will also contain the date code in which the part was manufactured. An example would be the engine code found on the Corvette’s engine block. This code can identify the engine’s origin and date of manufacture. The term, "matching numbers" implies that all parts on the car are numerically correct and the date of manufacture of those parts are correct for that Corvette. For example, if you’re looking at a 1969 Corvette with a 427ci. engine and the engine stamp indicates that the engine was built in early 1968, or even late 1967, that Corvette cannot be called a "matching-numbers Corvette". As parts break and need replacement, many owners, purchase the parts they believe are correct for the car, when in fact, numerically, they may not be. If you’re in the market for a "numbers matching" Corvette, and you’re not familiar with identifying build codes and date codes, you should probably take someone along with you that is knowledgable in that area.
Body-Off Restoration: Simply refers to the fact that the Corvette was restored and the body was removed from the frame in order to conduct a thorough restoration.
Frame-Off Restoration: Although slightly misleading, this term is the same thing as the above "Body-Off Restoration".