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what does numbers matching mean

74sundancekid

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Can someone explain what numbers matching on an engine means and how do I decode it? I have a 72 rally 340 challenger and am trying to figure out if I just need a 72 340 block or do I have to find the specific engine that is probably long gone to make it numbers matching. Thanks for the help!
 
To have a numbers matching engine it has to have at least the last 8 digits of the car's VIN stamped into it. Chrysler started doing this in 1968.
 
The importance of the “numbers matching” claim is directly related to the rarity and desirability of the car.
A numbers matching slant six Valiant isn’t going to be worth much more than the same car with a replacement engine.
A performance model car with its original engine will be different. 340, 383 4 barrel and larger engines make the biggest difference.
Once the “numbers matching” title got popular, all sorts of people started using the term in sales ads.
I’ve seen the term used in low performance type cars where nobody cares if it is the original engine or not.
I shake my head at that claim. I’ve seen ads of worn out projects with a picture of a restored example with the “this is what it could look like when finished” garbage in the ad.
To recap, the term means the engine that was in the car when it was built.
A distant second to this is what is called a “Date coded” block. That is a proper engine with casting numbers ( casting dates) appropriate for the year of the car. Often that means at least 3-4 months before the build date of the car.
Good luck.
 
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The importance of the “numbers matching” claim is directly related to the rarity and desirability of the car.
A numbers matching slant six Valiant isn’t going to be worth much more than the same car with a replacement engine.
A performance model car with its original engine will be different. 340, 383 4 barrel and larger engines make the biggest difference.
Once the “numbers matching” title got popular, all sorts of people started using the term in sales ads.
I’ve seen the term used in low performance type cars where nobody cares if it is the original engine or not.
I shake my head at that claim. I’ve seen ads of worn out projects with a picture of a restored example with the “this is what it could look like when finished” garbage in the ad.
To recap, the term means the engine that was in the car when it was built.
A distant second to this is what is called a “Date coded” block. That is a proper engine with casting numbers ( casting dates) appropriate for the year of the car. Often that means at least 3-4 months before the build date of the car.
Good luck.
thanks, sounds like I either get a date coded 340 or big block swap it
 
I think for most people it means the engine and transmission the car was born with. But you can go way further...
 
Can someone explain what numbers matching on an engine means and how do I decode it?

To have a numbers matching engine it has to have at least the last 8 digits of the car's VIN stamped into it.
Simply, this. ^^ The number stamped on the pad is the number on the car's VIN which indicates that it's the engine which was originally in the car at time of manufacture. Any other engine in the car is not "numbers-matching".
 
It was a GM thing that started in the late 70’s by Corvette guys. GM did not indicate the engine the car came with in the VIN until 1972. So a matching number on the engine block to the sequence # in the VIN verified if the car came with the L78 396, or the L79 327. Mopar has that info right in the VIN.

Btw… that applies to every GTO, SS Chevelle, 442, and Gran Sport.
 
In my book. Someone wants to make money when selling.
Doug
 
I think for most people it means the engine and transmission the car was born with. But you can go way further...
Power Steering pump assembly
Radiator
Differential
on and on and on
My Superbee is all original
383
Trans
Radiator etc...
I pulled out a date correct Hemi and it's sitting in my garage as car was originally a 383.
 
In between "matching numbers" on an engine and "date code correct" is-

warranty block

without serial number.
 
Having the original matching drivetrain is more desirable than non- numbers, and also worth more. So, in my case the purchase of my ‘71 GTX all numbers matching was why I pulled the trigger.
It will only continue to climb in value while I enjoy my summers with it.
 
I have a related question about my 1974 Road Runner. It was a factory 318, 4-speed car that was one of only 212 made that year according to Galen's White Book. Someone put a warmed over 1972 340 in it. My thought is that this car should have a 1974 318 (which I have) put back in it because of the limited production. Others seem to think that it should remain the same that it is since the original block is gone. I have no desire to sell, but thought for show purposes that returning it back to stock would be the proper way to go. Now, if it was an automatic car that has a production number of 5,421 units, then I would not feel the same way. Thoughts?
 
Nobody cares about a numbers matching 318...leave it under the bench and enjoy the 340
 
I have a related question about my 1974 Road Runner. It was a factory 318, 4-speed car that was one of only 212 made that year according to Galen's White Book. Someone put a warmed over 1972 340 in it. My thought is that this car should have a 1974 318 (which I have) put back in it because of the limited production. Others seem to think that it should remain the same that it is since the original block is gone. I have no desire to sell, but thought for show purposes that returning it back to stock would be the proper way to go. Now, if it was an automatic car that has a production number of 5,421 units, then I would not feel the same way. Thoughts?
Since the original engine is long gone, I would keep the 340, but dress it up as a mild mannered ‘74 318. That’s what I’m doing with my 66 Cuda, stroker 340 dressed up like a 273 2bbl motor.
 
I have a related question about my 1974 Road Runner. It was a factory 318, 4-speed car that was one of only 212 made that year according to Galen's White Book. Someone put a warmed over 1972 340 in it. My thought is that this car should have a 1974 318 (which I have) put back in it because of the limited production. Others seem to think that it should remain the same that it is since the original block is gone. I have no desire to sell, but thought for show purposes that returning it back to stock would be the proper way to go. Now, if it was an automatic car that has a production number of 5,421 units, then I would not feel the same way. Thoughts?
That's a toss up. Your choice there. If you were to sell it your 340 will probably be more popular to more prospective buyers. But, even with a 318 car, it is worth more to the purists with the original engine. If you don't have the original engine, I would just leave the 340 in it.
 
Rare does not always translate to desirable or $$. In the case of a 74 318/4speed RR, if you don't have the original engine any small block is going to make the car equally desirable and valued. In other words, leave the 340 in it and have some fun.
 
Who's looking at numbers when your rolling down the road at 75+?????
 
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