"Matching Numbers"

[Michel73]

When looking for "Matching Numbers" on the engine, is it the number that is stamped on the right side of the block below the valve cover on a piece of the block that extends out about 3/4" and about 1 1/2" long? The water pump and an A/C bracket is attached to this part of the block. If it is not here - where the heck is it? Thanks - Michel


Save the Wave

 

[Tom73]

That is the key number. On that stamp pad is the engine build code and the VIN deritive. Those along with the correct block casting and date casting numbers are what make a "matching number" engine. If there are not any numbers on the stamp pad then apparently the engine was rebuilt sometime in the past and the block was "decked" which resulted in the stamped numbers being machined off.

Also, for true matching numbers, there are VIN deritives on the transmission and on the frame. Those also need to match. Then there are all the parts numbers on things like the alternator, the distributor, etc that also have date stamps. These all need to be correct.

If all that matches then you may have a "matching numbers" car.

tom...

 

[ratdog]

and don't forget all the casting dates on the rear, seat rails, master cylinder, etc................................

 

[Michel73]

Thanks Tom and Ratdog for the info that was FAST
Right now I'm just trying to find out about my engine. I looked at it last night but I'm having trouble reading the numbers (looks like maybe two sets of numbers have been stamped) - is that the norm or should they be easy to read??? Thanks - Michel

 

[ratdog]

1 should match your vin, and the other is where it was built and the engine code and date

 

[Robert N]

As ratdog stated, there are 2 (last part of the vin and build date and suffix). They could be difficult to read.

 

[quickjagg]

re:

Mine were hard to read untill I rubbed the stamp pad with acetone, that cleaned out all of the dirt from the numbers.
Hope this helps,
-Chris

 

[Tom73]

Right now I'm just trying to find out about my engine. I looked at it last night but I'm having trouble reading the numbers (looks like maybe two sets of numbers have been stamped) - is that the norm or should they be easy to read???

Should be two sets of numbers stamped there. One will look like V1025CLA (V=flint plant, 1025=Oct 25, CLA=L48 Automatic) while the other will look like 1Z3S400001 where the last six match the last six of the VIN.

tom...

 

[sj20343]

I've read that some people don't regard transmission as part of a matching numbers car, however, I know that NCRS does require that the transmission be numbers matching. Would you guys consider mine a numbers matching car, based on the following?

I"m pretty sure that my transmission is not the original, it is a Turbo 400 automatic transmission rebuilt with shift kit, obvioulsy the shift kit is not original. I also know the small things like my alternator and exhaust manifolds are not origninal to the car.

My engine block and intake manifold are numbers matching to the vin. My frame also has the correct stamp on it as well.

If mine is technically considered a "numbers matching car" how hard would it be for me to get it there based on the above. Would I even be able to find the correct transmission?

Also, what is your takes on buying repro's such as repro rally sets instead of searching for originals?

thanks in advance.

 

[Robert N]

On a true matching numbers car, EVERY numbered part must be correct including cast and date codes. Today's definition tends to pertain only to whether the block is original. You could, with enough time and money, replace all numbers matching and date coded parts. Question - is it worth it?

For me to rebuild my NOM engine, the TI and A.I.R systems alone would set me back $3000. Add correct belts, hoses, clamps, screws, etc and I could have a $10,000 engine. I would be better off buying an already restored car.

 

[Tom73]

Would you guys consider mine a numbers matching car, based on the following?

I"m pretty sure that my transmission is not the original, it is a Turbo 400 automatic transmission rebuilt with shift kit, obvioulsy the shift kit is not original. I also know the small things like my alternator and exhaust manifolds are not origninal to the car.

My engine block and intake manifold are numbers matching to the vin. My frame also has the correct stamp on it as well.

If mine is technically considered a "numbers matching car" how hard would it be for me to get it there based on the above. Would I even be able to find the correct transmission?

Also, what is your takes on buying repro's such as repro rally sets instead of searching for originals?

Matching Numbers is a term that has a lot of shades of gray. (A lot of people use the term and have no idea of what they are saying.) If you are going for NCRS Top Flight or Bloomington Gold then you MUST have all numbers that match. As such you would need a correct transmission that was restamped with the right numbers. There is only three parts that must match the VIN on the car: the engine block, the transmission, and the frame. Those three are all that have the VIN deritive stamped on them.

To me, I much prefer the terms Original or Correct. Which would you rather have, a "matching number" engine or the "original" engine? No, they are not the same thing. A matching numbers can also be the original engine or it could be just a restamp. But then an original engine is not always matching numbers. It could have been rebuild and decked thus loosing the matching numbers. Then what is a "correct" engine? That would be one with the correct casting number and the correct casting date. It is one that could have been used in the car originally.

I try to keep the matching numbers in place if at all possible but do not see anything wrong with a "correct" part. It all comes down to the purpose of the car. Bloomington Gold or NCRS Top Flight, then you must have matching numbers. But matching numbers does not do one thing for drivability for a driver If the car is a hot rod then who cares about this subject? If it is a driver then you may want it to look somewhat correct. If it is a local show car then you may want it to look correct.

Me? I will pay extra for the matching numbers original engine car. Then I focus on keeping it correct. That way, if in the future, I can put in a bit of work and get it to "matching numbers" for the NCRS show circuit if I should desire.

It all comes down to what you want from the car. Just do me and the hobby a favor. True matching numbers/original cars are far and few between. Most Vettes were driven hard which resulted in engine failures. Thus replacement engines. So if you have an original car, please, please do not cut it up to make a hot rod. Save it for future generations. Sell it and go buy a non-original car to hot rod.

tom...

 

[sj20343]

My car is definitely not intended to be a hot rod. I always assumed that my car was not a complete "matching numbers/correct" car. As said before my engine is origianl/matching.

My only intention is to keep it orignal. I originally bought it a few years ago advertised as "matching numbers". The gentlemen that I purchased it from had all of the ducumentation which shows over $60,000.00 in restoration services. Over the years that I have had it, it has come to my conclusion through diligent research, that it is not a complete matching numbers car. I would love to someday get it on the NCRS circuit, but I am probably about 20% from being a full total numbers matching car. I should have done as much research before I purchased the car, but like you said matching numbers have different shades of gray. I don't, however regret buying it, I just probably could have gotten a sweeter deal since it wasn't a full "matching numbers" car.

I think all I need to do is buy a new transmission, but if I understand you correctly, it would only be "correct" not matching numbers, as it would be impossible to find the vin derivative transmission. Of course the small things like the alternator and exhaust manifolds, hoses, etc. would be somewhat easy, but costly to find.

I am a fairly young guy, and everyone is amazed that I try to keep it original, the older generations are proud that I have kept it this way. However, I am pretty new to the hobby, so it is hard to know if you are always doing the right thing, buying quality goods, and finding honest people to help you with your repairs, ect.

Its posts like this that help me out considerably.

thanks again, and would appreciate any advice or suggestions available.

 

[Tom73]

I would love to someday get it on the NCRS circuit, but I am probably about 20% from being a full total numbers matching car

Before spending a lot of money, take it to an NCRS event and have it judged. It might be better than you think. That will least it will give you a base line as to how original/correct the car is. Then you can invest you money where you can gain the most points. Say if "Item A" cost you 10 points but would cost $500 to correct while "Item B" was 25 points but only $400 to correct, then go for Item B first. Judging like this can make a very good road map for what needs to be done and the "cost benefit".

Good luck.

tom...

 

[68Roadster]

I too have tried to keep my 68 original/matching/correct, whatever is applicable at the time.

Recently I purchased new Lt/Rt and center grilles from a Chevy dealer for the car. These were sold under the guise of GM factory restoration parts. The ones that showed up did not look anything like my "originals" although they were in a nice little vacuum packed GM bag.

SJ - are your grilles black with the leading edges painted silver?? The supposed "replacement" grilles were solid black.

So when it comes to judging am I "correct" or SOL when it comes to having factory parts installed?

 

[Tom73]

Recently I purchased new Lt/Rt and center grilles from a Chevy dealer for the car. These were sold under the guise of GM factory restoration parts. The ones that showed up did not look anything like my "originals" although they were in a nice little vacuum packed GM bag.

SJ - are your grilles black with the leading edges painted silver?? The supposed "replacement" grilles were solid black.

So when it comes to judging am I "correct" or SOL when it comes to having factory parts installed?

You are caught in the "service" part vs. "production" part never-never-land. The Grills for a 73 have chrome leading edges. The 74 grills are identical except they are all black. Sounds to me like Chevy decided to just stock one part for both years and it was the 74 grill. Saves GM on inventory cost. For NCRS judging they would be wrong on a 73. For a driver they would look great.

tom...

 

[Paul Borowski]

You are caught in the "service" part vs. "production" part never-never-land. The Grills for a 73 have chrome leading edges. The 74 grills are identical except they are all black. Sounds to me like Chevy decided to just stock one part for both years and it was the 74 grill. Saves GM on inventory cost. For NCRS judging they would be wrong on a 73. For a driver they would look great.

tom...

This same instance applies also too '68/'69 front grilles. The service grille is the "all black" 2nd '69 style. If a '68 is to look correct, you'd have to buy the '69 style, and paint the leading edge of the grille bars Silver.

 

[68Roadster]

Paul, you are absolutely correct. I had to tape off my new "service" grilles and paint them. Funny it looked like rally wheel paint, thats what I used anyway.

That was a pain taping all that crap off. They look good anyway!

 

[sj20343]

68Roadster - My grills are black as well. This was one item on my list that I have planned to replace, but have never really looked into doing so. I think that I will do what you did and paint the edges. Did you use the rally wheel paint?

Tom73 - That is great advice on the NCRS suggestion. I just may try to do that. I was always scared of what I may find out!!!!

 

[68Roadster]

sj,
Yeah, spent about 2 to 3 hours taping each one off with masking tape and then about 30 minutes painting each one. The ones I removed (originals) looked like the color was rally wheel paint color. Sprayed it and they look great. Plus the replacement ones from www.Greenwoodchevy.com were alot beefier than the originals. I have no idea where you could even get the original style - already painted.

Oh well, not correct/original but functional. Looks good to me.

I don't ever plan to have mine flight judged or whatever so I try to use the best built/closest to original type stuff for my own peace of mind, not some judge.....

 

[JohnZ]

I've read that some people don't regard transmission as part of a matching numbers car, however, I know that NCRS does require that the transmission be numbers matching.

NCRS Flight Judging does NOT require that transmission (or axle) numbers be correct, and those numbers are not judged. Transmissions and axles are only judged for configuration and appearance, based on what can be seen with the car on the ground.

The only exception to this is "Bowtie" judging, which is only for 100%-original and completely untouched cars, and those cars are few and far between.