Called the previous owner to get the Numbers off the matching numbers motor in his garage 2000 miles away and he said they were ground off while DECKING
Is this possible ? Where would I get the numbers to STAMP back on ( from GM ? )
Is this common?

 

Yes, this is not only possible, but common. It happened on my Camaro. A giveaway is the angle of the grinder cuts on the number pad. Original cutting marks run straight front to back. Decking cuts are somewhat circular.

Restamping has been done, but I have no idea where to go to pursue it. Sorry!

 

What makes you so sure this motor is 'numbers matching' if they've been ground off? (Gawd, I still hate that term, numbers matching)

Even if it is the original block, what would you gain by restamping it? This is always easy to spot, and could be perceived as an attempt to defraud.

Just chalk it up as another awpoopie!

 

In no way am I condoning this, nor do I have any experience with restamps, but if you get a copy of Hemmings Motor news, and look under Corvette parts and services, there is always vendors of vintage Corvette short and long blocks for rebuilding. I have seen them advertise "stamping service available". I assume that is for engine pads. :D

 

You see and hear of MANY stories like this. I've read a number of posts here on the Forum about this very problem. I just don't understand it. I've had several original engines rebuilt, and I just tell the guy DON'T deck it. I'm building street engines, and I feel that there is NEVER a need to deck a block. If it's stayed together for 60, 70, 100K miles like it is, why do it?

A lot of guys are just looking for the "cheapest" rebuild possible and go to an assembly line machine shop...a lot of guys just don't know. If you've got an original motor Corvette, and you deck the block, you've lost 10 to 25% of the value of the car IMHO. It's a very stupid mistake. Chuck

 

Like Chuck said a lot of the "speed shop" type machine shops don’t care about numbers on the deck. My block was decked with no visible signs having done so and the heads fit correctly with no leaks. A quality machine shop can stop short of the pad.

While they are avenues for duplicating the stamping, duplicating the broach marks created on the pad at the factory is another story. Which allows for an easy warning of a re-stamped block pad(By no means am I implying that you are trying to defraud, just commeting) . ;)


[Modified by Robd, 9:46 AM 11/20/2002]

 

There are people who CAN restamp and replicate the broach marks if you are having the car judged and don't want to sacrafice the points. Before expending the money however, I would confirm that all other indications are that it is the correct block for your car. Nothing worse than spending a couple of hundred bucks restamping your block to find out later that the block was cast 3 days after your car was built! This may sound rather elementary, but it happens on a regular basis!
This restamping is allowed by the rules and if the work is good enough to pass muster, then you may take no point deducts for the pad. If you are not having the car judged and only wish to do this to increase the car's value at time of sale then this is fraud and I would not reccomend it.

:seeya


[Modified by John McGraw, 10:45 AM 11/20/2002]

 

John,
I didn’t realize this technique was perfected...that’s sad.

 

I guess that all depends on which side of the fence you are standing on. There are many who have original engines who hate that others can replicate an original stamp pad, because it devalues their truly original engines. Then there are those who want to replicate the pad stamp for judging,and don't really care about other peoples value. Unfortunately, there are those whose sole purpose is to convince an unsuspecting buyer that the engine is original in order to squeeze more money out of the car.
From my point of view, there is nothing more sinister about restamping an engine then there is about demanding a perfect reproduction set of carpets.
We are constantly striving to re-create a corvette just as it was when it was delivered by the dealer, and this is just one of the components.
Keep in mind guys, this is a HOBBY, and more importantly this is a GAME, a game we choose to play when we restore corvettes for judging! We only play by the rules that are established by whoever's feild we are playing on. In this case it is the NCRS flight judging rules which set a point value on the pad stamp and broach marks, and we would not be playing the game very well if we did not try to maximize our points! I am lucky enough to have the engine that came in my car from the factory 43 years ago, but make no mistake about it, If it did not, I would endeavor to replicate the most perfect pad stamp that I could, to maximize my points. Furthermore, I don't view any person who has such an eye for detail that they can produce a perfect stamp pad as anything but a true artisan, and worthy of the same respect as the painter that can replicate a truly original looking paint job! The true value of a restored car is in the overall quality of the restoration and not wether a car has the correct pad stamp on it.
Let the flames begin!
:seeya


[Modified by John McGraw, 12:06 PM 11/20/2002]

 

I agree with John. What is the difference between restamping an engine pad and restamping a generator tag, or distributor tag, or... They are all restamps.

Yes, it can be done correctly, and it can be made undetectable. I guess I am in the minority when I say a restamp is no big deal. Restamping, in my opinion, is just part of the restoration process.

 

No flames here, John, your points are accurate, in my humble opinion.

In fact, I would take it a step further- if you are restoring a Vette to NCRS specs, you are increasing the value of the vehicle. I don't think anyone will argue that having a Top Flight or other award ever devalued a Vette. If having the block stamped makes the car that much more accurate by the rules of the NCRS judging game, then why not do it? It naturally follows that the dollar value would be raised because the vehicle is more accurate. Notice- I'm not saying more original, simply more accurate. Let's face it- there are damn few completely original Top Flight or better cars. Most are restorations to greater or lesser degrees. So why should it be a problem to have the block stamped?

Now, if you have a Vette which isn't ever going to be judged, doesn't fit that profile whatsoever, then having a restamp can only serve one purpose- fraud.

Luckily, I have asbestos underwear. Flame on, if you will. :wave:


[Modified by Mac, 12:29 AM 11/21/2002]

 

I can easily walk both sides of the fences here.
1. It's great a technique exists that will allow an owner to re-stamp honestly.

2. I own a numbers matching BB '68 that is not documented very well. I have owned this car long before it was profitable to re-stamp incorrect cars. And have always felt solace to the fact anyone who can spot a re-stamp can verify that mine is the real deal. And it looks as if that edge is gone. :confused:

 

Rob,
One real problem is that there are a lot more people who think they are pad stamp experts then there truly are. I own an early 60 car, which has the original stamp with almost no visible broach marks. This coupled with the fact that early 60 cars had the VIN stamped without the aid of a gang holder, gives the pad the appearance of being stamped by an amateur! The truth is that a nice fresh blade on the broaching machine will leave almost no marks, the more worn the blade becomes the more marks it leaves behind. I have had more than one "stamp pad expert" view my pad and proclaim it incorrect, but the judges who really know their stuff know it for what it is, a nice example of an early 60 pad stamp.
I would probably end up with less controversy on my pad if I had "restored" my pad with fresh broach marks and nice stamping, but it is original so I will continue to try to educate those judges who think it is incorrect. Judging is a very subjective process and everybody has their own opinion of what looks correct, and you just can't take it personally. Just take pride in the fact that YOU know the stamp is original! At the end of the day, you may get the same points with a restored or an original, but it is a real source of personal pride to know it is original, even if it does not translate into higher value.

:seeya :seeya


[Modified by John McGraw, 10:48 AM 11/21/2002]

 

John thanks for your input!

I agree that they are many original marked blocks out there to some look as if they were done in someone’s backyard. The broaching machine blade must have dull that day in Tonawanda because my marks are pretty obvious. And I also agree that seeing how I most likely will never sell my car it really doesn’t matter just thinking out loud.:hat

 

Rob, one thing I like about owning an original engine 68 is that who would bother to go to the trouble of restamping a 68? :lol: If I had paid $100k for a 67 435 hp car there would always be that doubt..... do I own a real car or a skillfully crafted replica? MJ

 

I guess I have to jump in and defend our 68s.No I didnt have my block restamped.But I will tell you what I know.There is a company in Hemmings that will rent you the stamps to restamp your engine ,as mentioned earlier in this thread.That company also will sell you a "100%" matching numbers restored engine for your vehicle.I wont lie ,I called them before buying my crate engine ,to see what their prices where.They were going to sell me a matching number 327 ,restored down to every nut and bolt for approx. $4500.I decided against it because #1 I thought it was dishonest .I wouldnt have sold it as such ,but someone later would have.#2I like my 68 but it wasnt worth a $4500 for a base 327.#3 someone told me afterwards that it could have been spotted if it was magnafluxed during a future machining for a rebuild.#4 9-11 hit and a crate 350 looked pretty good for $1200.. :seeya :yesnod:

 

MNJack,

I do agree with you however, I guess I am a great believer that one day the '68 Corvette will break loose of it's stigma and become a legitimate collector car. Riding on the shirttails of the '67 Corvette is not an easy task. However I also fell that that in it self has helped pull the '68 along to a degree. In 1988 when the '67 BB started the skyrocket the '68 damn near doubled. Anyway one day, you gotta have the faith!:D

 

One thing I have noticed from the many restamps I have seen. It is not the characters themselves that are the hard part of restamping. The hard part is getting the pad surface to look correct.

Broach marks of some sort are almost always present, even with a sharp broaching blade. You may have to use a magnifying glass to see them.

The other problem is removing the existing numbers. This is tough to do, and make it undetectable. That is one reason that virgin pad blocks go for so
much money.

Remember, "matching number" is NOT the same thing as "original engine".

 

To Verify the Matching Numbers , Could that Stamp pad area be X-Rayed like they do for Cracks in a block.
Could it be polarized , and have iron filings poured on the area , which would form the missing matching numbers
Would a magnaflux process show the hidden numbers
Any other ways , that others have used for verification

 

If the pad has been ground off smooth in the decking , it is possible to recover the numbers but whether it's worthwhile or not is the question as the process to raise the serial number involves removal of even more material from the pad.

The serial number on items such as motor vehicles, firearms, bicycles, and motorcycles are commonly removed or altered in an attempt to prevent the identification of the original owner of the item. The serial number can sometimes be restored depending on the degree of obliteration or alteration.

When a number is stamped into a metal object, the metal underneath the number is compressed and hardened. If the number is ground off, this hardened area may still be present. By using an acid solution the metal can be slowly eaten away. In this process the softer metal surrounding the stamped area will be eaten away first and the number may reappear. This is commonly referred to as "raising the serial number".

Obviously, if another stamping is done over the pad, this would also compress and harden the metal further, marking it more difficult to raise the original number but that's not the case for your motor (yet). I would say if the casting number is consistent, rent the gang stamp and get it over with.