Matching numbers?
Determining Matching Numbers
By Mike "Doc" Cobine
18 December 1996 Updated June 28, 2004
Matching numbers is a term tossed about with ease, as is restoration. Both are found in most Corvette ads today as an indication that this Vette is somehow better to buy than one without. This document will attempt to clarify some of the issues and show how to determine what matching numbers really are.
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http://www.geocities.com/MotorCity/D.../matchnos.html
Note that there's an important distinction between the term "original" and the terms "correct" or "numbers-matching"; they're two entirely different things.
Now about that "Vintage Racer" stuff, I've only registered for two vintage races in my life - one at Moroso in '88 to test the car (and lost the $50 test engine) and one at Tamiami in '88 where they refused to let me run since I had a real racing license and a real old race car. (Just as well, they wrecked about 6 or 7 cars.)
I was just a bit crazy taking a 35-year-old race car into current racing competition.
I have read this article with huge interest. Very well explained, thank you.
There are two questions which still remain after reading through this thread, let's make some examples:
1. Example:
If I have a Midyear Corvette which reamains original, means it has all the original parts. Let's assume it has a Powerglide automatic transmission originally. If I exchange this transmission to a Muncie 4-speed transmission which fits regarding the date stamps, then I lose the originality of the car for sure. But it should be still matching numbers right? I'm not sure yet if all transmissions on C2 corvettes have the VIN stamps on the transmission. If they have, I will also lose the matching no. Correct?
2. Example
Let's assume that I have (or any seller out there) a matching numbers Covette which has a not much preferred body color or interior color. If I repaint it to black and change the trim tags accordingly, is there any way to identify this by checking VIN numbers against Trim Tag or something? I mean, if the Trim Tag looks original, I can check all numbers on the Corvette and it seems to be numbers matching, but the color has changed.
These questions maybe sound strange, but I just want to be as much informed as possible before I maybe paying for something a Corvette isn't. I also already ordered the Corvette Restaruation Guide Vol. 2.
"Matching numbers" is a term that seems to mean different things to different people. Ask 10 people and you'll probably get 6-8 different answers. Truthfully, I think most people at least want to see the engine stamp be real (not a re-stamp) and match the VIN and build date of the car, and the interior and exterior colors match the codes on the trim tag.
1) All 63-67 Corvette engines have a VIN derivative and an engine assembly date that includes a suffix code that identifies what the engine is. Besides identifying the engine type, the suffix code also indicates whether the engine was originally attached to a manual or automatic trans. If you swap a manual trans into a car that originally came with a Powerglide, it will be instantly identifiable to anyone familiar with 63-67 engine suffix codes. Additionally, all 63-67 transmissions came with a VIN stamp, identical to the one on the block.
So to your question, no, once you change the trans, the car will no longer be "matching numbers", the engine suffix code will identify that the trans has been changed.
2) The only correlation between the trim tag and the VIN number, is the body build date on the trim tag.
Each trim tag has a code identifying the month and day (month & week for 63's) that the body was built, and that build date needs to correspond to the car's build date. It's pretty easy to find out when a Corvette was built, from it's VIN number. There are readily available charts on line, to find a Corvette's build date, based on it's VIN.
Repro VIN tags are usually stamped with a date code to match the VIN, but that doesn't guaranty that you will fool anyone by using to a repro trim tag. Repro trim tags can usually be identified by most trained judges and Corvette appraisers. There are anomalies to the real trim tags, that fortunately, none of the repro's have seemed to duplicate.
Because of the desirability, and rarity of original black cars, trim tags on cars with black paint, usually come under far more scrutiny, than most other trim tags. A repro trim tag on a black car will almost always get caught by somebody.
In the future, you may want to post your questions in the C1/C2 General section. Far more members regularly visit the C1/C2 Section, than the "Factory Correct" section.
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So, how to determine "matching numbers" on one of the early cars.
I have a friend that has a 1957 270 hp 4 speed car. It was a late 57 build car, so the 4 speed was available. The date codes for the car absolutely matched the car, and the car had all of the appropriate parts on it.
Only problem was, the car was not an original 270 hp, 4 speed car.
My friend had a seriously wrecked 1957 270 hp 4 speed car. He also had a very nice all original 1957 220 hp powerglide car. The 220 hp powerglide car was 3 VIN digits different than the 270 hp car.
You know what happened. My friend removed the 220 hp powerglide setup, and installed all of the 270 hp 4 speed parts on the now ex-220 hp car.
He put the 220 hp powerglide stuff in the wrecked now ex-270 hp car and sold that as a project. That car got restored to NCRS top flight quality. This car was originally black with silver coves and red interior.
The now not quite original, but certainly matching numbers 270 hp 4 speed car is still around, but had been off the road since the mid 1980s. This car was also originally black with silver coves and red interior.
Last edited by emccomas; Oct 19, 2017 at 03:32 PM.















