VIN Number Stamp Question: Engine/Trans

[ClassicCars]

I was looking around to buy a low mileage '87 Grand National, I came across an original car with approximately 10K original miles with great owner history.
While looking at the partial VIN number stamped into the pad of the engine block and the side of the transmission case, I found that the two numbers matched each other.
"4HP4XXXXX".
Here is my question: Those two stamped numbers that were on the block and trans where one digit off from the car's actual VIN. (VIN tag, RPO Sticker, Window Sticker.)
Example: The last eight digits in the car's VIN are: HP123456, The engine block and trans had: HP123457 (The last digit was incremented by "one".)
It was like there was a problem on the assembly line and pulled one engine/trans setup off the line and took the next engine/trans and kept going.
Did anyone ever seen this or heard of this?
I'm 100% sure this is the "original" power train in the car. Was it "Stamped" wrong or the assembly line's quality control wasn't that good back then??
Thanks for you help, Bill

 

[pacecarta]

driveline error is first for me
in the extended end run they were making nothing but gns , my 87 got the build sheet (in th driver door) from the next car , last number of vin on that paperwork as one higher than my dash vin
on driveline you would expect that they would be sure to be accurate but seems with yours they made a mistake stamping . i dont know if the stamp was automated or hand done but the driveline had a scan code stickers and can only assume that matched the paperwork for your build

 

[grass doctor]

driveline error is first for me
in the extended end run they were making nothing but gns , my 87 got the build sheet (in th driver door) from the next car , last number of vin on that paperwork as one higher than my dash vin
on driveline you would expect that they would be sure to be accurate but seems with yours they made a mistake stamping . i dont know if the stamp was automated or hand done but the driveline had a scan code stickers and can only assume that matched the paperwork for your build

wow that's pretty crazy pacecarta...and only someone like your self would probably catch that ...

 

[Anthony P]

Hi Bill, I would only be speculating what happened in your specific scenario, so I won't...

it was a manual stamping process...view some old pics of the process in this thread from a 'Vette forum...

https://www.corvetteforum.com/forum...-how-were-the-engine-pad-numbers-stamped.html