C1 & C2 Corvettes General C1 Corvette & C2 Corvette Discussion, Technical Info, Performance Upgrades, Project Builds, Restorations

Help on restamp question

Thread Tools
 
Search this Thread
 
Old 04-29-2024, 05:41 PM
  #1  
elongo
2nd Gear
Thread Starter
 
elongo's Avatar
 
Member Since: Apr 2024
Posts: 2
Likes: 0
Received 0 Likes on 0 Posts
Default Help on restamp question

Ok so I recently bought a 1965 Corvette. The last 3 numbers on the deck have been stamped over to match the vin Does anybody know if GM ever did this because I ran the other numberunder the restamp and it is 1 day prior of production date of my vin. ????? Or do you think someone found a correct date coded block that was close to the vin # Im baffled
Old 04-29-2024, 05:45 PM
  #2  
Nowhere Man
Team Owner
 
Nowhere Man's Avatar
 
Member Since: Feb 2003
Location: Sitting in his Nowhere land Hanover Pa
Posts: 49,162
Received 7,017 Likes on 4,821 Posts
2015 C2 of Year Finalist

Default

There was a such thing as factory grind outs where they did such things. How you tell them apart from someone who did it 50 years later I have no clue
Old 04-29-2024, 05:47 PM
  #3  
Factoid
Le Mans Master

 
Factoid's Avatar
 
Member Since: Jul 2018
Location: San Antonio, TX/Mahopac, NY
Posts: 8,455
Received 5,637 Likes on 2,833 Posts
2024 Corvette of the Year Finalist - Modified
2024 Corvette of the Year Finalist - Unmodified
2023 C7 of the Year Winner - Modified
Default

Please post a pic. That will really help.
The following users liked this post:
John BX NY (04-29-2024)
Old 04-30-2024, 11:45 AM
  #4  
elongo
2nd Gear
Thread Starter
 
elongo's Avatar
 
Member Since: Apr 2024
Posts: 2
Likes: 0
Received 0 Likes on 0 Posts
Default


i ran the vin under the car vin and it says that car was produced 1 day before my car???????????
Old 04-30-2024, 03:48 PM
  #5  
rowingone
Burning Brakes
 
rowingone's Avatar
 
Member Since: Jan 2006
Location: Longmont Colorado
Posts: 1,136
Received 264 Likes on 167 Posts

Default

The factory did do odd things . . here is a pic of my original rear frame stamp from the factory. The front vin stamp was correct and not like this "mistake".

Old 04-30-2024, 04:46 PM
  #6  
vettebuyer6369
Administrator
 
vettebuyer6369's Avatar
 
Member Since: Jul 2000
Location: About 1100 miles from where I call home. Blue lives matter.
Posts: 51,514
Received 5,364 Likes on 2,788 Posts

Default

Originally Posted by elongo

i ran the vin under the car vin and it says that car was produced 1 day before my car???????????
Its kinda believable, actually.
The following users liked this post:
Factoid (05-02-2024)
Old 04-30-2024, 04:52 PM
  #7  
Vettrocious
Melting Slicks
Support Corvetteforum!
 
Vettrocious's Avatar
 
Member Since: Sep 2009
Location: MI
Posts: 3,122
Received 1,122 Likes on 577 Posts
2023 C2 of the Year Finalist - Unmodified
2022 C2 of the Year Finalist - Unmodified
2017 C2 of Year Finalist

Default

Well, three possibilities 1) it’s factory re-stamp on an engine that was pulled the previous day for a repair, or other odd reason. Not likely, as the factory would not have even tried to align things so perfectly. 2) It’s a factory stamp (for the earlier car) where someone re-stamped the VIN back in the day (before anyone cared about originality) and put it your car. Or 3) it’s the dumbest, most bubba’d restamp ever.
Old 04-30-2024, 05:11 PM
  #8  
Uncle Pasko 73
Pro
 
Uncle Pasko 73's Avatar
 
Member Since: Aug 2019
Location: New Orleans
Posts: 662
Received 577 Likes on 265 Posts
Default

How about... the line worker picked up the wrong gang stamp, one from yesterday, stamped it, went "Oh, ****" when they realized what happened, then fixed it.
The following 2 users liked this post by Uncle Pasko 73:
dcamick (04-30-2024), Factoid (04-30-2024)
Old 04-30-2024, 05:39 PM
  #9  
65GGvert
Team Owner
 
65GGvert's Avatar
 
Member Since: Jul 2006
Location: Kannapolis NC
Posts: 20,624
Received 3,243 Likes on 2,316 Posts

Default

Originally Posted by Uncle Pasko 73
How about... the line worker picked up the wrong gang stamp, one from yesterday, stamped it, went "Oh, ****" when they realized what happened, then fixed it.
why would he have one laying around with 200 cars before that one’s vin and it hadn’t been changed.
The following users liked this post:
L78 (05-02-2024)
Old 04-30-2024, 05:50 PM
  #10  
vettebuyer6369
Administrator
 
vettebuyer6369's Avatar
 
Member Since: Jul 2000
Location: About 1100 miles from where I call home. Blue lives matter.
Posts: 51,514
Received 5,364 Likes on 2,788 Posts

Default

Originally Posted by elongo
Ok so I recently bought a 1965 Corvette. The last 3 numbers on the deck have been stamped over to match the vin Does anybody know if GM ever did this because I ran the other numberunder the restamp and it is 1 day prior of production date of my vin. ????? Or do you think someone found a correct date coded block that was close to the vin # Im baffled
I have to ask, did you know this before you bought the car?
Old 04-30-2024, 06:12 PM
  #11  
rowingone
Burning Brakes
 
rowingone's Avatar
 
Member Since: Jan 2006
Location: Longmont Colorado
Posts: 1,136
Received 264 Likes on 167 Posts

Default

The "twos" do not look the same . . the curve on the second "2" doesn't match that of the first so . . my guess is restamp by a non factory person.
Old 04-30-2024, 06:13 PM
  #12  
AOS_L79
Racer
 
AOS_L79's Avatar
 
Member Since: Apr 2010
Posts: 366
Received 52 Likes on 46 Posts

Default

Only the last 3 digit positions were stamped twice. How would that have been accomplished with a gang stamp? The alignment looks pretty good except for the 4.
Old 04-30-2024, 06:14 PM
  #13  
Uncle Pasko 73
Pro
 
Uncle Pasko 73's Avatar
 
Member Since: Aug 2019
Location: New Orleans
Posts: 662
Received 577 Likes on 265 Posts
Default

Originally Posted by 65GGvert
why would he have one laying around with 200 cars before that one’s vin and it hadn’t been changed.
Because that was the last car it stamped, then they went to a new one. Laid it aside when it probably should have been put it away somewhere. At some point it accidentally got picked up?

That's my guess... and it seems more plausible than someone just happening to find an engine from the previous day and doing the worlds worst restamp in an attempt to counterfeit matching numbers



Old 04-30-2024, 06:15 PM
  #14  
Nowhere Man
Team Owner
 
Nowhere Man's Avatar
 
Member Since: Feb 2003
Location: Sitting in his Nowhere land Hanover Pa
Posts: 49,162
Received 7,017 Likes on 4,821 Posts
2015 C2 of Year Finalist

Default

Originally Posted by AOS_L79
Only the last 3 digits were stamped twice. How would that have been accomplished with a gang stamp? The alignment looks pretty good except for the 4.

would be interesting to know how the off line heavy repair section of the line handled engine stamping if a problem occurred.
Old 04-30-2024, 06:29 PM
  #15  
AOS_L79
Racer
 
AOS_L79's Avatar
 
Member Since: Apr 2010
Posts: 366
Received 52 Likes on 46 Posts

Default

Originally Posted by Nowhere Man
would be interesting to know how the off line heavy repair section of the line handled engine stamping if a problem occurred.
It doesn't seem likely that someone offline doing repairs would know what vin the engine would need stamped on the pad.
Old 04-30-2024, 06:32 PM
  #16  
Nowhere Man
Team Owner
 
Nowhere Man's Avatar
 
Member Since: Feb 2003
Location: Sitting in his Nowhere land Hanover Pa
Posts: 49,162
Received 7,017 Likes on 4,821 Posts
2015 C2 of Year Finalist

Default

Originally Posted by AOS_L79
It doesn't seem likely that someone offline doing repairs would know what vin the engine would need stamped on the pad.
it would be if at the end of the line they had a failure
Old 04-30-2024, 06:54 PM
  #17  
gbvette62
Race Director
 
gbvette62's Avatar
 
Member Since: Oct 2000
Location: Shamong, NJ
Posts: 11,167
Received 2,073 Likes on 1,341 Posts

Default

I believe Al Grenning is the foremost expert on Corvette stamp pads in the world. Al has spent the last 40+ years studying and photographing engine stamps, and has interviewed the people at Tonawanda, Flint and St Louis responsible for stamping the pads. Al regularly does seminars for the NCRS on stamp pads and I've been to a number of them. From what I've learned, typically when a mistake was made when stamping a pad at either the engine plant or the assembly line they did a grind out. A grind out is just what it sounds like, they took a hand held grinder, ground off the mistake and restamped the pad with the correct information. From photos I've seen it's pretty obvious when a grind out has been done because the grind out leaves an obvious circular grinding mark under the stamping.

I've never seen a pad that had a new number stamped over another one, except in the case of a double tap, and I'm not sure it's even possible for it to happen with a different number on the assembly line. How the gang holder was used as described by Al Grenning, was that at the beginning of each shift the gang holder was loaded with the first VIN to be stamped. Once that first block was stamped, only the digit(s) that needed to be changed for the next VIN were removed from the holder and replaced. If the first VIN stamped was xxxxxxx410003, only the "3" was removed and replaced with the "4". This would continued till they got to 10009, at which point both the "0" and the "9" would be removed and the "1" and "0" were added. This would continue till the end of the shift, when the gang holder was emptied completely. It was probably done this way because the person doing the stamping probably didn't have the time to empty and fully reload the gang holder for each VIN, and there was no need to completely empty it for just one or two digits. If this is the way that they stamped VIN's at St Louis, and I believe it is, there's no way that a block would be stamped with three wrong digits unless they were going from "099" to "100", "199" to "200" etc., which is not the case here. Occasionally something would happen like dropping the gang holder and the stamps would fall out and need to be reloaded, but even in this case if a mistake was made it would likely be made by putting the right digits in the holder, in the wrong order. From the numbers I see on that pad that couldn't be the case with this VIN.

I'm not willing to say that it's 100% not a factory screw up, if for no other reason then the broach marks are there and look good, but what I see is completely outside what I've learned would be how a mistake was usually corrected.

This is a pad that really would be worth having Al Grenning at CCAS Affirmation review, but the cost to do this is not cheap. I think he's now charging around $1500 for his expertise.

https://www.ccas4vettes.com/
The following 2 users liked this post by gbvette62:
blue_74 (05-04-2024), provette67 (04-30-2024)

Get notified of new replies

To Help on restamp question

Old 04-30-2024, 09:10 PM
  #18  
John BX NY
Drifting
 
John BX NY's Avatar
 
Member Since: Dec 2006
Location: Bronx New York
Posts: 1,827
Received 348 Likes on 234 Posts

Default

Factory grind outs and restamps are very well documented...overstamps not so much.
Old 05-01-2024, 04:22 AM
  #19  
DAN70
Burning Brakes
Support Corvetteforum!
 
DAN70's Avatar
 
Member Since: Dec 2008
Location: PURCELLVILLE VA
Posts: 1,080
Received 258 Likes on 176 Posts
C1 of Year Finalist (performance mods) 2019
2017 C1 of Year Finalist

Default

Do both VIN’s still exist today?

DAN
Old 05-01-2024, 07:11 AM
  #20  
gbvette62
Race Director
 
gbvette62's Avatar
 
Member Since: Oct 2000
Location: Shamong, NJ
Posts: 11,167
Received 2,073 Likes on 1,341 Posts

Default

Originally Posted by gbvette62
This is a pad that really would be worth having Al Grenning at CCAS Affirmation review, but the cost to do this is not cheap. I think he's now charging around $1500 for his expertise.

https://www.ccas4vettes.com/
As an update I was informed by Al that his fees vary based on things like the year of the car and the particular engine. He told me this pad would be $750 to review, not $1500.


Quick Reply: Help on restamp question



All times are GMT -4. The time now is 06:00 PM.