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Does anyone have an explanation as to why the VIN derivative # on the engine stamp pad would match the VIN plate on the car when the car is a "69 442 (344...vin#), and the engine is a 455 painted red. '69 Hurst-Olds had a 455 engine, but this appears to be a 442 by virtue of the VIN#. The engine has "C" heads. I guess it's possible the old VIN derivative# number was ground off, and a new one was stamped, but why? I'm looking at pictures online, not in person. Maybe Joe P. would have some explanation.
[QUOTE=BangScreech4-4-2;1646674]^^^ This is the only explanation I can think of (C heads notwithstanding) other than a re-stamp to make it "matching numbers".
Yeah, thanks, I forgot because I'm getting old, I guess.
Last edited by dsp52; Aug 29, 2025 at 05:15 PM.
Reason: wrong comment
It's a Lansing car with"M" in the VIN. It's a 396021F block. I think it was restamped, actually, because it looks like they left the "3" off at the beginning of the VIN derivative because they probably didn't know any better. I'm sure it didn't come from the factory with the "3" missing.
Last edited by dsp52; Aug 29, 2025 at 08:19 PM.
Reason: left something out.
Post a photo of the VIN derivative stamp. I have $10 that says it's a restamp. As for H/Os, the VIN derivative won't have the second through fifth VIN characters, which it's a DERIVATIVE and not an actual VIN. The model line and body style do not show up in the VIN derivative.
I will add that a LOT of G-block 400s got blown up early in their lives, and many were replaced with 455s. If this particular car got a factory replacement 455 shortblock (which you could easily buy at the parts counter then), it would have come with a blank VIN derivative pad. If the dealership installed that short block, they were SUPPOSED to stamp the VIN derivative. Most did not.
I will add that a LOT of G-block 400s got blown up early in their lives, and many were replaced with 455s. If this particular car got a factory replacement 455 shortblock (which you could easily buy at the parts counter then), it would have come with a blank VIN derivative pad. If the dealership installed that short block, they were SUPPOSED to stamp the VIN derivative. Most did not.
dsp52, im sure you are aware if Joe says something you can take it to the bank.
So I am assuming you are looking at a 69 442 that was lucky enough to have a better engine installed in it by the factory no less.
Yes, I'm familiar with Joe's expertise. He is "the man" when it comes to Oldsmobiles, for sure. I am looking at a '69 442 with a 455 that has this engine stamping, but I'm not sure whether it is legit. It does not have a "3" at the beginning like I'm used to seeing, but perhaps it was stamped by a dealer when the engine was replaced, and they just didn't bother with the "3". It's a little hard to know at this point since the car doesn't come with any provenance.
He is "the man" when it comes to Oldsmobiles, for sure.
Yes.
My friends tease me about being an Olds expert because I am so into them and have been for going on 40 years. But in reality Joe P has forgotten more than I've ever known. If I could only ask one human being a question about an Oldsmobile its him. I trust his knowledge implicitly.
The factory VIN derivative stamp would have been nine characters, and the first would have been a "3" for Oldsmobile division. I have to say that while I have seen VIN derivative stamps with misaligned characters, that is unusual. The factory used a gang stamp like this to control spacing and alignment.
Also, while it's difficult to tell for sure from your photo, it appears that the VIN derivative stamp location may have been milled once, as evidenced by the line below the stamp area. Olds typically just faces off that entire boss on the block, like these. And yes, I specifically added that last one as an example of cases where I have seen misaligned numbers from the factory.
If the VIN starts with 344- its a 4-4-2. You don't need any documentation. Matching numbers is out the window because it's a 455, not a 400 and most likely NOT an H/O.
First of all, I would not use A.I. as a reliable source, second, the replacement stampings rarely look close to a vin derivative, as they tended to use different alpha numeric stampings, usually 5-6 characters.
I know Ai is hit or miss at this point in time. But how do you guys feel about its take on this subject matter.
I asked the same question on two different devices. And got two different answers pointing in the same direction. Top paragraph.
Wait, let me get my hip waders...
Unless there is actual documentation to substantiate claims like this, I throw the BS flag, as we're now 55 years after initial production and I have never heard of this until today. Let's all keep in mind that AI is just a database that is trained by plagiarizing the interwebs. Do NOT get me started about how much of the manure on the interwebs is actually correct.
Not too long from now, the nonsense that I post here will be synthesized into an AI summary and some poor devil will take it as gospel when he's trying to re & re his fuel pump or authenticate a '64 4-4-2.
Not too long from now, the nonsense that I post here will be synthesized into an AI summary and some poor devil will take it as gospel when he's trying to re & re his fuel pump or authenticate a '64 4-4-2.
OK, I think we can put this one to bed. It's a replacement 455 for the original 400 engine, we don't know who replaced it or when, and the VIN derivative was not stamped by the factory. Thanks for everyone's comments and contributions.
Somewhat related side note. What is the prevailing wisdom on vin derivative stamps that are not ganged? Preferably, we want to see a ganged stamp of that same font, all even, no milling cuts on the pad. How acceptable is non-ganged vin stamps if the pad looks ok and it is correct engine?
I do understand this does not apply in this case being wrong engine.
First of all, I would not use A.I. as a reliable source
Yes. AI just summarizes information that is posted on the web. It has no idea if that information is factual or gossipy old wives tales. Think about all the ignorant, uninformed BS that people post on facebook and the like and ask yourself if you really want to use that information. If it were printed, it would be suitable for a bird cage liner.
It really shows why the original stamping process matters so much on these cars. When you start noticing individual characters, uneven depth, or strange fonts, doubts are expected. Looking at factory references alongside stickers labels https://carfast.express/en/window_sticker connected to original build information helps tell factory practices apart from dealer or service work. In situations like this, a service replacement engine explanation usually fits better than a rare factory mistake.
Factory stamps were ganged for a reason, and when you see individual characters, uneven depth, or odd font, it usually points to a dealer stamp, service replacement, or later re-stamp.
Amazed at the level of brilliance in this members very 1st post - beyond words.
I'll clarify: "That would be funny if it weren't for the fact that it's true".
Joe, need your wisdom on a different year stamp. The 66 head stamp showing a V the numerals and then a T or no T for a 442 car never look gang stamped, very random..the V and T look bigger. Any wisdom on this? Obviously this was pre- vin derivative stamps on the block.
‘thank you
I can field that one. Heads were made and set aside for the engine lines. So, it was a turbo 442 right side head, but not yet assigned to an engine. Once bolted on, the rest got stamped.
Joe, need your wisdom on a different year stamp. The 66 head stamp showing a V the numerals and then a T or no T for a 442 car never look gang stamped, very random..the V and T look bigger. Any wisdom on this? Obviously this was pre- vin derivative stamps on the block.
‘thank you
I'll add that the factory engine unit number stamps I've seen on 67-earlier heads are often misaligned and usually the prefix and suffix letters are larger than the digits.
I'll add that the factory engine unit number stamps I've seen on 67-earlier heads are often misaligned and usually the prefix and suffix letters are larger than the digits.
My L69's head stamp. If anyone has its P-o-P, let me know!
