Double vin stamp
 

So while rummaging around the shop, i stumbled upon a 70 judge engine. Turns out it belongs to the owners car which is a total rust bucket, but he's not giving it up. Anyway, while searching the numbers, i found the vin number is stamped twice on it. Has anyone ever seen anything like this before?

Yep, my 69 t/a has a double stamp just like that. Thought it was odd, but I've heard of it happening.

seen it numerous times

Wild. I figured that would throw red flags everywhere.

I've seen a few, including on zero value 350 2bbl type engines so it's definitely a thing.

If the stamps were done manually in a hand gang I would be a little surprised (because that represents more manual work).

But - if they were done mechanically then I would not be surprised at all.

I supervised the chassis line in the truck plant where the "secret" VINs were stamped into the frame.

The VIN stamper is a large hydraulic "press" hanging from a tool rail and with the weight offset by a "balancer" (imagine a Harley-Davidson hanging from the ceiling that you are supposed to deftly maneuver into position and press a button - 60 times an hour). It is supposed to index to the next digit automatically -but - pretty regularly it would mis-hit, not hit, or double hit. Often nobody would notice until the vehicle was twenty or thirty job stations beyond the stamp operation.

If the number was wrong, or missing, that could be a problem. For the correct number simply hit twice - I'd let that fly.

K

Some doubles I've seen are because one of the numbers are off by a digit and the others because the first was stamped too crooked (the top or bottom portion of the numbers are not stamped deep enough).

at least a dozen times.
have also ran across two smog era 400's & 3 originally installed 455 HO engines which had no confidential VIN stampee on them. keep in mind, I pulled a crazy amt of 400's & 455's from the mid 80's up into the mid 00's.

first occasion, I can remember on a notable Pontiac engine was near 40 years ago with a '70 YZ 400 which I bought as a runner, carb to pan. The partial VIN gang stamp was stamped at an angle with the last few digits, so lightly stamped, they were not discernible. Next to that string of numbers was another stamping. That what I assume was the later stamping, the last few digits were more legible, but the top of the characters were light stamped. The original PQ mated to that late May '70 cast YZ, shared the same partial VIN, but also had two barely legible characters at the end.

Have also had two Pontiac blocks, that instead of a pair of kinda parallel stamped partial VINs, the stamping of one partial VIN was stamped at an angle over top of the original partial VIN. This left one character in the middle of the string, hard to read without a magnifying glass.

Off by a digit is another story.

For those we would have to make a repair. Different division names (ie, Chevy/GMC, or Buick vs Olds vs Pontiac) may have different VIN sequence numbers, requiring different stampers hanging there, so if the operator stamps a Chevy VIN on a GMC, for example, then not only is that particular vehicle wrong but you are out of sequence on every job after that.

The assembly line repair person and/or the "quality man" (the foreman's right hand man) follow the vehicles down the line with an "X" stamp and a 5 lb hammer and correct the VIN sequence number as required. Repairs were "X"d out, never repaired by grinding.

Usually it's not just one vehicle. It normally takes several builds before somebody notices, especially if things have been up to that point running smoothly and you are "in the zone". That means you'll have five or six vehicles that have to be fixed - all without the line stopping - so it's quite a scramble for a few minutes while you figure out what went wrong and what has to happen to make it right, especially at 60 or 70 jobs per hour (= one completed vehicle off the end of the line every minute). You pray nothing else goes to crap while you've got your two best guys otherwise unavailable.

At one time I would have said that we caught all the mistakes, being a federal regulation and all, but I have seen enough mis hits in my time as a hobbyist to believe some (...many...) got out.

K

Had a 70 YZ from Oshawa Canada plant with double strike.
My former 73 SD from Norwood was double strike
And seen many others here and there over the years.

So it could happen at any given plant at any given time.
Most blocks I have encountered were normal routine single strike .

I'm curious if anyone has seen a triple stamp?

Sure have, the stamp on this 1979 400 W72 block I had bought a while back had been stamped a bunch of times. For some reason, I see it a lot on the 78-79 400's, i'll have to go find a photo of it. Take a look at this 1978 T/A stamp, this one was bashed in a whole bunch of times.