I did a search to learn more about matching numbers, but didnt quite find what I was looking for.

My question is, what all components have the "numbers" on them, and how do I find out that each one is "matching"?

Also, if a number is not matching, is it not possible to bring it back to "matching", or is the possibly swapped out part gone for good?

I have a 1974 L48 and dont have a clue about these numbers that I hear alot about when people talk about value, resale, or just vintage history.

Thanks!

 

Matching numbers are the engine block and all major components (rear, tranny, anything that is dated and has a casting number). First you have to find out what is right for your car, head numbers, block numbers, rear codes, tranny numbers ETC. Most things are dated, from water pump to seat tracks (my 69 were). Everything must fall before your body build date and production date (inside driver door tag). You have to be good at math and it is fairly easy to decode things HAHAHAHAHA. As for replacing dated things, everything can be replaced with the correct part except the 2 things that have the vin on them, the block and the tranny (at least my 69 4speed is), other than those things, as long as you get the right casting number and the right date range, CONSIDER IT MATCHING!!!!!! GOOD LUCK...........................Get some books to find what numbers you should have or need.......................B

 

Here's a good one for determining originality. The appendix has all the numbers for the major components.

 

You will have to find your year. But theres alot of info here..


http://www.corvetteactioncenter.com/...1969/69id.html


http://www.chevy-camaro.com/chevy-ca...-code-help.asp


http://wiki.corvettefaq.com/index.php?title=Main_Page


http://corvetteforum.net/c3/1970regi...ocdetails.html

 

Pick up the "Technical Information Manual & Judging Guide" for your year car. It will have all the info your looking for.

www.ncrs.org

 

If I remember right NCRS gives you like a 6 month window on either side of the build date in order to be considered 'matching'. So a 12/12/1974 car would be considered NCRS matching if all dated parts were dated between 6/12/1974 and 6/12/1975.

I also belive this allows you to be matching #'s but not original for vin dated parts like the engine.

But I'm not an NCRS guy, so one of them will have to chime in.

 

The 6 month window is considered correct for most parts but it has to be prior to the build date.

 

Just to be super ****, there's a little difference between "correct" and "matching."

Proper date codes on many parts are acceptable within certain windows, such as the 6 month guideline used by NCRS on engine production. However, having a date-coded part like that means the part is acceptable, correct, appropriate, whatever word you want to use, for the relevant application.

However, the real use of the term "matching" comes into play when the parts in question bear a VIN, which actually "matches" the VIN on the body of the car. For example, a Corvette with a VIN derivative on the engine block pad which "matches" the actual VIN found on the car, is a true "matching number" car, and is the source of the most value taken in a relative context.

Some Corvettes, such as the pre-'60 cars, don't even have a VIN stamped on the pad, so while the motor may be "correct," "appropriate" or whatever given the casting number and casting date, it can't really "match" anything and is easily replaced with no concern of whether it was original or not.

I suppose the color codes on a trim tag could be considered "matching" when compared to the body color/ interior trim of a car, too.

**** for sure, but remember many sellers absolutely love to fuzz up the concept of "matching numbers" simply to represent a car as more correct than it really is. I believe in our hobby its better to be more picky than less when it comes to eventual car valuation.

Oh, and anti-numbers guys, go ahead and flame on.

 

What a coincidence, I was just using matching numbers as an example on searching the Internet for information.

Here is the Yahoo search.
http://search.yahoo.com/search;_ylt=...h&fr=yfp-t-501

I said that you can find the information you want if you are clear in your search criteria. Searching for "Corvette" will yield hundreds of thousands of results, and you may not find anything related to what you need until the 100th page or later.

But if you want to determine matching numbers for your Corvette, then searching for "determining matching numbers Corvette" will be much better.

The first one up in that search is this and it is linked to in several of the other links:

Determining Matching Numbers -http://www.geocities.com/MotorCity/Downs/3000/matchnos.html

 

Correct. Parts cannot be dated after your car was assembled.

 

Let me throw my two cents worth in here.

When "most" people talk about matching numbers they are usualy refering to the engine block matching the VIN.

But there are 4 parts that have the vin, the body, the frame, the transmission, and the block. If these 4 match, then you have a great start.

To the collector and NCRS geek, matching numbers include all numbers and date codes on the car. In other words, all the parts numbers must be correct for the car and any date code must predate the build date of the car. That can be lots of numbers and codes

So all this comes down to what you want to do with your car. Looking for NCRS Top Flight or Bloomington Gold certification? Then the numbers are very important. Looking for a driver to have fun with? Then numbers don't matter. Then you have all levels inbetween.

It is all up to you. It is your car to do with as you please

 

Actually, there are 3 locations where there is a derivative of the Vin#, the pad on the block, the tranny and the top side of the frame near the drivers rear wheel. Don't know when they started stamping the frame but Ihave read this in several refrence guides.

 

I agree completely that it is his car and he should do as he pleases. I also agree that his intended use for the car should guide him in the level of correctness and matching he pursues, if at all. No one can say anything is good or bad, it's all personal choice.

I would however, add that the fact is, the closer to correct and matching, the better it generally reflects on value. I'm not starting a modified vs original debate. I'm just stating that closer to correct generally correlates to more value and more buyers, more often. That's why regardless of what your personal choice may be, I would remind him that the numbers do matter, even if you choose not to worry about them, at least in many cases.

The guideline I always used in my classes was, there's nothing wrong with having something custom, modified or not original; just don't pay original prices for it, that's all.

 

Way, way back in the C1 days.

 

There is a simple formula to the madness... Non match anything.. reasonable price. Matching engine, tranny... Price of cheese is getting higher. Matching alternator, distributor, carb, plug wires... you get the hint.. the ultimate.. High.. But be forwarned..it is addicting and unless you buy a total one owner, window sticker. tank sticker proof LOW mileage documented car, anything is possible.( I can't believe they changed out the rearend and went with 4:56's )

 

Wow, that was a little eye opening. I have no intention of ever selling my new prize, im just looking to know all about it I can.

Thanks everyone for the replies! Now I get to dig a little deeper and see just how "correct" mine still is! I appreciate all the help guys!

 

Since a couple of you guys certainly seem to have a lot more knowledge about this than I do, the whole build date thing made me think of something. Lets say you bought your car new in 1968 or something, and while it was in the warranty period you had to take it back to the dealer for something ... maybe something as minor as a water pump or as major as a transmission. They replaced it and sent you on your way and you never had a day of trouble with it.

I think you can see where I'm going with the question ... basically you now have a car that doesn't have the "original" part, but only because the original part was defective, and the new replacement part would have a date later than the build date. Work was done by the dealer, it's a genuine part, etc. How does this affect the price/perception whether documented or undocumented?

I'm not personally in this situation, it just came to mind after reading the 6 months/build date comments.

 

Another 2 cents...the sidepipe shield covers, also have the derivative of the VIN# as well.

 

Buy the corvette by the numbers book, It will tell you everything.

 

A more exstream example would be a blown engine and the dealer replaced it under warranty with the standard "CE" replacement engine. In the numbers game, the car is no longer original. What is looked for is a car as it was delivered to the dealer. A water pump is no big problem, you can find the correct part and replace it. But for those stamped with the VIN, there is only one and once it is gone it is gone forever.

tom...