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explanation of matching numbers


Guest connl

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I'm trying to determine if my car has matching numbers. I own a 1965 Olds Dynamic 88 convertable. Can anyone suggest where I research this subject? A bit confused by what I have seen so far. I noticed a section in Year One's Cutlass catalog, but not sure it applies to Dynamic 88s. Not only would I like to determine how to match the numbers, but I need info on where to look for the numbers on the engine / trans / other parts. Thanks. Larry

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First, "matching numbers" is the most mis-used term in the collector car hobby (with the possible exception of "classic"). Starting in 1968, the Feds required a VIN-derivative to be stamped on the engine block and transmission. For Oldsmobile this VIN-derivative was nine characters long and comprised of the first character and last eight characters of the car's VIN. If these numbers match each other and the VIN, then you can be assured that the car has the original engine and trans and this is "numbers matching" (or that the block and trans have been restamped, which is a different problem). Your 65 predates these "VIN-derivatives", so there really aren't any numbers to match.

Having said that, there are other, less definitive things like casting numbers and date codes. A certain year and configuration automobile should have specific parts, so these casting numbers must be correct for that factory build configuration. In addition, major items (block, heads, manifolds) will have cast-in date codes, which should predate the build date of the car by one to three months. As I said, these are not definitive since Olds built thousands of cars in that one to three month period. Having a date code or casting code that is clearly incorrect is proof that the part is not original, but just because it is in the correct range doesn't prove it's original. Finally, on the pre-1968 cars Olds stamped an engine unit number on the front of one of the heads. This number does not match the VIN, but certain characters in the number can provide additional (but again non-definitive) proof of originality. For example, the 65-67 442s carried engine numbers that started with the letter "V". A 442 of that vintage without one of these engine numbers clearly doesn't have the original engine.

Whenever I see a pre-68 Olds that is advertised as "numbers matching", I immediately ask the seller to please point out the numbers that "match". Of course, there aren't any.

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Joe,

Great explanation. I have a few numbers from the engine. Maybe you can tell me what they mean? There is a casting stamp on the block with the number 386525A. There is also a 4993 nunber stamped int a machined surface area of the block. One head has the number M064184L stamped on it. Is there anything you can teach me about these numbers? Thanks.

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I would like to add slightly to Joe's excellent answer.

First, I would like to suggest that the most overused term in our hobby is "rare"; followed by "classic" and "numbers-matching".

But as to there being no numbers to match prior to 1968, I must respectfully disagree. As Joe points out, a vehicle is produced with certain parts, many of which carry either a casting number or a date code or both. And while, again as pointed out by Joe, it is impossible to prove that a specific part is ORIGINAL to a vehicle; it may be proved that a part is CORRECT as far as production for that vehicle.

Many judging authorities and enthusiasts feel that matching for correctness is important; and some judging authorities feel sufficiently strongly that they publish lists of the various casting numbers, and a suggested date "window".

Many of these judging authorities have "original" classes and "modified" classes. Too many non-matching numbers will cause the vehicle to be judged in the modified classes.

Jon.

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Taking the above 1 step further for your specific vehicle:

In 1965 Oldsmobile used 9 DIFFERENT 4-barrel carburetors and 11 different 2-barrel carburetors.

Just looking at the 4-barrel carburetors, the best commercial rebuilders "group" the 9 different 4 barrel carbs into only 2 groups. These they build to their own specification (which is never the same as any original specification). Some of the less expensive commercial rebuilders have only 2 groups of 4-barrels from 1959 to 1965!!! Will a 1959 carburetor work on your 1965? Probably. Will it work as well as a properly calibrated original as calibrated by Rochester to Oldsmobile's specifications? NO WAY. As the commercial rebuilders are aware of this, the identification tags are removed from the carburetors. This is one of the reasons why some of the auto parts store parts are less expensive than if one visits the original factory dealer.

So to summerize, your 1965 would have a carburetor identified by a tag, with a calibration specific to the original engine, transmission, and whether or not the car was equiped with air conditioning. This number is published, and your carburetor is either "numbers matching" or it is incorrect.

How important correctness is would be a decision of the individual.

The same can be said for engine blocks, heads, distributors, generator/alternators, transmissions, differentials, etc., etc., etc.

Jon.

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Guest JRZYBOB442

To add more to this topic. Joe is correct about "matching numbers" - I'd also like to add the word "original" to our list of overused words.

On a more serious note, while pre-68 cars do not have a specific matching number, the engine code stamped with the "engine number" can, at least, tell you if the engine was the right one for the car. The Chassis Service Manual usually indicates what this code might be. For example in '65 the codes are:

33400, 33600. 33800 = T

35200 = U

35400 - 38600 = "M" for 2 bbl; "N" for 4 bbl.

Transmissions have a usage code tag attached which does give a manufacturing date, in some cases, and always the usage code. Same for the rear end.

You can contact me off line @ bob.gerometta@wildaboutcars.com and I will provide you with scans of the appropriate pages from the 1965 Chassis Service Manual.

The Chassis Service Manual can be acquired in CD format from Gearhead Cafe - www.gearheadcafe.com.

Bob

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  • 3 weeks later...
  • 2 months later...
Guest will62super88

Have you tried sending your info to the GM Heritage Center.

(gmhc@gm.com) Another thing you might wan't to check out is a web site I found for my 1962 Super 88, I know it's not the year of your car but it has helpful info and site's.

(http://home.comcast.net/~oldsfan/MySite/62oldspage.html)

Luckily my car had come with the Protect-O-Plate witch has helped me know for a fact my car is origanal and has what it came with. So I hope this info can help you.

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  • 3 months later...

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: JRZYBOB442</div><div class="ubbcode-body">To add more to this topic. Joe is correct about "matching numbers" - I'd also like to add the word "original" to our list of overused words.

On a more serious note, while pre-68 cars do not have a specific matching number, the engine code stamped with the "engine number" can, at least, tell you if the engine was the right one for the car. The Chassis Service Manual usually indicates what this code might be. For example in '65 the codes are:

33400, 33600. 33800 = T

35200 = U

35400 - 38600 = "M" for 2 bbl; "N" for 4 bbl.

</div></div>

Hello everyone. This thread was of particular interest and especially timely for me. As a quick background, I have a 64 Buick Riviera (ROA 11550), a 61 Chevrolet Impala 2-dr, and a 66 Ford Thunderbird convertible in various states of restoration. Deciding I wasn't busy enough, I began looking for a 66 Olds Tornado, found a project/fixer upper on ebay, submitted a low ball bid and wound up winning the thing.

The vehicle is presently in Oklahoma City, and coincidently I happened to be there for work this past Thursday and Friday. The plan is to have a local shop get it roadworthy and then return to OKC and drive it to Denver next weekend to put in storage. (I guess part of the adventure was picturing my buddy and me roaring down Oklahoma interstates in a primer colored Toro ala "Fear & Loathing in Oklahoma City")

But I digress. When I looked under the hood yesterday as part of a quick inspection (I had a flight to catch), I began to have doubts about whether that engine belonged to that car. I have a 66 Olds Shop Manual at home, but couldn't remember where or what to look for to verify the engine correctness. I found a few numbers cast into the intake manifold, heads, etc, but the one number I did find and record "389244" was located on the block just above the water pump.

So, until I have a chance to access my shop manuals, any additional info on 1966 Olds Toronado engine codes (so I can tell the shop where to look to help determine correctness) would be appreciated.

thanks in advance

alex bonino

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I've answered my own question. A little internet research revealed the following:

"389244" is the engine block code for 66-67 Olds 425 ci engine

Engine block casting number is found at the front of the engine, on the horizontal ledge just above the water pump (which by luck is where I happened to look)

Determined this info at the olds 442 website, which has a wealth of Olds casting number decode info (beyond just the 442) and has not been mentioned yet in this thread:

http://www.442.com/oldsfaq/ofblk.htm#Blocks

hope this info helps others

alex bonino

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<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: alex bonino</div><div class="ubbcode-body">Determined this info at the olds 442 website, which has a wealth of Olds casting number decode info (beyond just the 442) and has not been mentioned yet in this thread:

http://www.442.com/oldsfaq/ofblk.htm#Blocks

hope this info helps others

alex bonino </div></div>

While your were successful, don't believe everything at that FAQ. That FAQ is simply a compendium of posts from the old Oldsmobile email list server from 10-15 years ago. Some of it is correct, some is not. It has the same problems as Wikipedia, but with less vetting... and I even wrote some of it.

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  • 9 years later...

 

On 12/5/2007 at 11:34 AM, joe_padavano said:

Whenever I see a pre-68 Olds that is advertised as "numbers matching", I immediately ask the seller to please point out the numbers that "match". Of course, there aren't any.

So my 32' Olds DCR, which has the same number stamped on the engine block, stamped on the frame in two places, and stamped on the body tag nailed to the wood body sill is NOT a matching number car?

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  • 3 months later...

My 32’ is a F32, 6 cylinder, wood wheel, deluxe with a total production of 249 units. After 2 years of research and many conversations with many knowledgeable people, I’ve been able to locate only 2 other original wood wheeled F32 roadsters. One restored, one not. So with the information I posted earlier and info in this post, please tell me why it would be inaccurate to say my car was a “matching numbers, rare car?” Judging by everyone’s comments here about pre 68’ examples, making that claim would be incorrect. 

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chistech  in your case I think "numbers matching" is the wrong terminology.  My Series 6-30B Pontiac has the original engine.  This has been verified by a letter from General Motors stating the date of Assembly and the engine number that was put in my car.  The numbers are correct for this car but they do not match.  The documentation says it is the right engine that was put in that serial number car.  The provenance is there so the statement would be a 1930 Pontiac serial number 1xxxx2 was assembled in Regina, Saskatchewan on June 6, 1930 using engine number P7xxxx8.  In my case I also have the documentation through to my Grandfather's purchase of the car in Winnipeg in August.

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On 9/24/2017 at 5:30 PM, chistech said:

So my 32' Olds DCR, which has the same number stamped on the engine block, stamped on the frame in two places, and stamped on the body tag nailed to the wood body sill is NOT a matching number car?

 

That is, in my opinion, the exact definition of a "matching numbers" car. It was almost never done in the prewar days. Apparently Oldsmobile in 1932 is an exception.

 

The practice of stamping the same number in different locations became common in the US auto industry in the late 1960s. The number of locations stamped increased as time went on.

 

 

Edited by Bloo (see edit history)
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4 hours ago, Tinindian said:

chistech  in your case I think "numbers matching" is the wrong terminology.  My Series 6-30B Pontiac has the original engine.  This has been verified by a letter from General Motors stating the date of Assembly and the engine number that was put in my car.  The numbers are correct for this car but they do not match.  The documentation says it is the right engine that was put in that serial number car.  The provenance is there so the statement would be a 1930 Pontiac serial number 1xxxx2 was assembled in Regina, Saskatchewan on June 6, 1930 using engine number P7xxxx8.  In my case I also have the documentation through to my Grandfather's purchase of the car in Winnipeg in August.

Not sure why you think the term matching numbers doesn’t apply to my car. Your car has the original components but they are numbered differently while all components in my car have the exact same number. Why wouldn’t you consider all the same number as matching? They’re definitely not non matching and I’ve never heard the term “same numbered” car. So, if not a matching numbered car, what would you call it? I would call your car original, with correct numbers but I assume you might consider it a matching numbers car because it matches the factory correspondence. With my car, I don’t need factory correspondence to show that the numbers match as they are there stamped into the car and are all the same. 

      With only 19,xxx Olds made in 32’, and 16,000 of them 6 cylinders, there’s is very little known about that year which is evident by the posts here as it seems no one knew on this thread other than me, that Olds did indeed stamp the engine block, chassis (in not one but two locations), and the body tag on the sill all with the same exact number originally at the factory. This number is different than the body number, and the car number. All DCRs had the same body number (32418) and the car number simply tells one when that car came off the production line in Lansing. So to me the blanket statement of “people using the term of matching numbers is a joke on anything prior to 68’ “ is totally incorrect in some cases, including mine. Also, with a total of 733, 6 cylinder roadsters made in 32’, 249 of them wood wheeled, 6 tired models, only 9 total units known including one hot rodded, and just three of those wood wheeled, the rare description seems to fit in my opinion as basically we’re looking at 1% of total model production still in existence on a very low number of units produced originally.

Edited by chistech
Added words (see edit history)
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It appears that your Oldsmobile is one of those things that disproves the "rule".  I certainly was not aware that any GM's stamped their cars this way.  I apologize for my previous statement.  Your car certainly is "numbers matching".  It would be interesting to know when Olds started doing this.  I had a good friend that had many cars in his collection, including a 29 Olds like the one his Father had owned.  We talked about lots of things and he saw the documents that I have from GM but never mentioned anything about Oldsmobile serial numbers.  I have always believed that any day your don't learn something is a wasted day.  Your post 16 has prevented this day from being wasted.

Once again my apologies.

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My father told me the same thing and I’ve taught my son also. We do learn something new every day and if you don’t, you’re probably not open to learning or feel you’re already to smart for everyone else. ( don’t mean you as you, using it in generic terms). I’ve done an extensive amount of research on the 32’ Olds model year and have spoken with what is considered the most knowledgeable men on the 32 Olds. Those men include Rush Wright, Shelly Wright, Jim Conoran, and Joe Pirrone. Through my research and conversations I’ve learned the things that most don’t know or recognize on today’s restored 32’ Olds. Things like placement of pinstripes, width of pinstripes, fully chromed horns where only the bell of the trumpet is chromed, open sheet metal joints that have been filled during body work, etc.. Yet, with these deficiencies from original, these cars have been national show winners because people just don’t know. That is why I made a point about the broad statement of matching numbers. Perhaps I’m too anal in my Restorations as I can research just a simple 32’ fastener for days and often end up machining what I need rather than using the closest available if it’s not 100% correct. I know I’m not alone as my good friend and fellow Olds restorer, Joe Pirrone, is just as anal. He and and I are currently working at manufacturing or own offset rubber muffler hanger bushings. One has to think how many people/judges would even look under the car then look at the muffler hanger. The difference is both joe and I know what those bushings should be and if not for people like us and others that go to that extent, the real truth about our cars gets lost and a simple statement like the matching numbers one can easily get accepted as the truth when it isn’t.

      I personally made a statement a few days back but used the term “I believe “ because I’m not 100% certain my statement is factually correct. That statement was that flat or satin paints were not invented in the early 30’s. I made this statement because men I know with original factory documents from DuPont and other paint manufacturers told me that all those paints are listed as gloss and that satin or flat was not invented. But, with all that info, no one has been able to definitively say when those two finishes were invented.   Some will swear they’ve seen flat paint much earlier but often those paints have just lost their shine or were sprayed more as an overspray rather than a good wet coat like they should have been. When the true facts aren’t there, we really can’t be sure and need to be careful how we make statements as our statements could easily but unwantedly, change the real truth.

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