Numbers Matching

[grumptruck]

So after roughly 30 years of playing with Muscle Cars and knowing how important the correct part numbers can be in verifying the authenticity or correctness of a particular car, Im wondering how this applies to our trucks.
I own a '67 C3500 and it is very original with les than 68k miles on it.

I see numbers everywhere. On the firewall, on the hood, the engine block, the trans and rear diff etc....
While playing under the hood yesterday, cleaning etc, I noticed some numbers on the brake booster - Yellow stamp of BB and some stamped in numbers (not casting) on the master 133 1k It happens to be a 133" wheelbase 1 ton.
Do these numbers correspond or are they just random ....

I'd love to learn if there in fact a way to verify what parts are original to the truck

[harpo231]

Random ,, The spid and vin should match frame numbers and sometimes block.
If built in Canada they can send you all the info.

[Coley]

GM didn't put the VIN numbers on the motors of the trucks until the early-mid 70's.
So the block contained a simple stamping that indicates the motor size, the transmission type, the vehicle type/size (ie: 1/2 ton, 3/4 ton) and where and when the motor was built.
However, you will not find the VIN number on that block.
The GM cars were different....the block stamping including part of the VIN.

The trucks transmission will have a similar identifier on it.

All of that said, 'matching numbers' is not really possible with these trucks...but you can do enough math on the motor to know the motor is probably original.
As a result the same level of value relative to a car's originality does not really make it into the trucks at the same level.
In other words you won't get too much of a value premium for an original motor/trans truck vs. a high quality upgrade or replacement drivetrain.

My two bits.
Coley

[truckster]

Originally Posted by Coley

In other words you won't get too much of a value premium for an original motor/trans truck vs. a high quality upgrade or replacement drivetrain.

Or degrade the value by updating components.

[harpo231]

what he said !

[davepl]

If you have a date-realistic engine with the correct casting, that's as close as you can get. But consider my 1970 396 TH400 truck: the engine is coded to 1970 396 automatic truck, so it's a pretty safe bet that it's the original. But you can't prove it authoritatively, even with GM of Canada documentation.

[grumptruck]

Thank you all for the info. Ive learned that there is really no production date on these trucks either. Interesting that there aren't any real documents that list correct part #'s for specific model trucks.

My father owned a classic vette and man-o-man every single part was able to checked and verified. Same with my other cars.

I guess that's what in part makes these trucks so much fun. No worry of crazy rare original parts. Just put 'em to work like they were intended.

[jocko]

In the grand scheme of things, on these trucks - VINs can be cross-checked and verified that they represent the truck one is looking at, but engines and transmissions, etc can really only be dis-proven as original. That's not so bad, if you're not trying to fool anyone as a seller, and just like the trucks because they are your style as a buyer, then I'm glad it doesn't get too sticky over the whole numbers matching thing. Where it DOES come into consideration is when one is talking about the closest a 67-72 can get to being a blue chip original, as in a 72 swb 402 super, and things like that - when paying high dollar at BJ's one better be able to at least confirm the numbers that CAN be proven as correct all line up - and that the drivetrain at least can't be dis-proven. I think that's where the general discussion on here tends to go - disproval of originality since that is possible (and common) as opposed to proving exact originality, incl drivetrain, which is darn near impossible. Personally, I enjoy deciphering a truck's history, but it doesn't mean I don't want one that isn't "original". I have one 72 with a GM crate and one with a swapped 350 from Lord knows what. Would I rather have the known original engine - yes, if it hadn't been bored twice already, but still, I'm just fine with my run of the mill mills.

[grumptruck]

I too also really enjoy the research and history associated with each truck.
I like looking over things and learning whats correct and what's not.
Im pretty sure that much of my truck is original. Its fun to expose an original marking and/ or number. Automotive Archeaology!

[ho70]

Numbers matching applies to muscle cars per value as many small V8 Camaros were sold, but only a few had 396's etc. Anyone can buy a Camaro etc, but only those with money could afford a SS 396 or COPO so they are rarer hence the price increase. To find one with the original engine is rare as most were raced in the day. Our trucks I think get more money for condition and options: big blocks, ac supers etc. than a #'s matching one (which apparently doesn't exist)

[pryorstemmed]

I saw a thread awhile back that had numbers on the protecto plate that matched a number on the engine block. You need the protecto-plate in order to know if you have the correct, "numbers matching", original engine block.

[71CHEVYSHORTBED402]

All kinds of stuff. Primary seems to include the door & door jam tags, SPID, build sheet, frame, title, original documentation & protect-o-plate.

Most parts have a stamp or tag of some sort, including the hardware. You can trace down to year or close. For example, if you search for the casting number on your block, the internet will provide the years the block was built. If it matches the truck, then as Chevy trucks are concerned, the numbers match.

Some parts include a part number and build date, such as an intake manifold. As I recall, every date stamp on my truck is a month before the truck was built. Gives you some idea of their inventory flow. Combined with the part number casting bumped up to GM inventories and applications, the "numbers" most definitely match.

[GASoline71]

Of course ALL the Corvettes, Certain Chevelles and Camaros have value for "numbers matching" as they had specialty engine and transmissions and suspension packages available. Trucks are utilitarian in nature, and there were no specialty engine options or performance suspensions available. So, "numbers matching" to these trucks doesn't really apply to any kind of value other than sentimental value.

Having the original engine in one of these trucks that came between the frame rails from the factory is definitely cool. I have the original engine in my 1972 GMC C1500 (well... the block is original anyways)... but I would never offer it up as numbers matching and try to gain more money for it.

Gary

[davepl]

Originally Posted by GASoline71

Of course ALL the Corvettes, Certain Chevelles and Camaros have value for "numbers matching" as they had specialty engine and transmissions and suspension packages available. Trucks are utilitarian in nature, and there were no specialty engine options or performance suspensions available. So, "numbers matching" to these trucks doesn't really apply to any kind of value other than sentimental value.

I believe my all-original 402 truck to be worth a lot more than an L6 truck.

Some trucks were purely utilitarian, to be sure. Mine is not. It was ordered by a family who used it for vacations and camping and ordered it with a lot of options. It was the Escalade ESV of its day.

To me it matters that my truck has the original engine (or at least so far as it can be proven). And I would not have paid what I for it if it didn't, so it definitely impacts value a lot beyond sentiment.

I would wager, though, that numbers matching only matters for a small set of trucks like mine or like a 4x4 SWB where you're paying a lot of money. But agreed that it's not as big a deal breaker as, say, a Corvette.

[DeadheadNM]

Took some time to look at the protect-o-plate from my blue blazer. A POP stands as good documentation that the truck has the original drive train components when present and seems a close equivalent to a "numbers matching" passenger vehicle. Shown are photos of the POP together with the engine block and transmission codes (don't have a photo handy of the axle code).

Sorry this photo isn't the best but the embossed codes for the engine and transmission are a match.

[DeadheadNM]

....

[DeadheadNM]

...

Edit: the code on this 1972 th350 is stamped onto the oil pan and iirc it's the RH side. Unlike passenger vehicles there's no code stamped plate affixed to the transmission.

[Chevyland]

Yep
That’s about as (matching #s) as you can get
In these trucks!!!

[Chevyland]

Hey Pete

I know the full stamp number on the front of the block is on the pop
And it sounds like the number from the tranny is on it too
Are you saying the axle code is also on the pop

Can you tell me where the stamps are on the axle as well as tranny

I just picked up a truck that is as original as I have ever found
I have tons of documentation and the pop
The engine matches, now I’m curious about the others

Thanks

[bruceman1968]

1971 to 1972 Chevrolet light duty truck PoP layout

[muley]

Originally Posted by bruceman1968

1971 to 1972 Chevrolet light duty truck PoP layout

Attachment 1767392

For just 71/72, or will a 69/70 be the same? I'll have to dig my POP out of the safe and take a gander at this.

[GASoline71]

I think having the original Protect-O-Plate is cooler than anything "numbers matching"..

Gary

[DeadheadNM]

There ya go. Thanks Bruceman. My build month code is an embossed "B" for February.

[arcticman]

Hello everyone, great topic for discussion. I'm also interested in researching originality of my truck.I'm a new member to this site. I have a 67K1500 swb wideside that I believe is a low mileage unmolested truck. I dont have the POP but the build sheet is still behind the seat. I was working on the truck the other day and noticed an ID tag still attached to the exhaust manifold gasket. That tag matches the #on the build sheet.(upper left corner in photo) I find in hard to believe that a truck that's 50 years old would still have this tag hanging off the engine. Did GMC use POP's?

Scott

[davepl]

Protecto plates are available that say SCOOBY DOO (or anything you want) for about $300, so it's a piece of evidence if you have it, but not authoritative.

I think the best documentation you can have is the original build sheet. Mine was stuck in the paint of the front of the bed...