About 3 years ago I bought a '68 big block and was told it was numbers matching. The dealer is a reputable dealer and I believe he is right. I've attached photos of the VIN plate on the windshield post and the stamping on the passenger side of the block. If you look closely at the block stamping you can see faint stamping behind the more obvious stamping.

I'm considering selling the car and want to be prepared to explain the "numbers matching" claim. I need some experts.

 

Clean the paint off the pad with some solvent to see it better

 

There is an extra 4 on the engine pad compared to vin.. Car is listed on the c3 registry with this "Motor is a period correct 1968 427, has been rebuilt".

 

Listen to Ralph

 

That block has obviously been restamped. I have never heard of one leaving the factory with an extra digit. No way to prove it was the block installed at the factory now. What does the tranny stamp look like? The block and tranny were both stamped at the same time, with the same gang stamp, by the same person.

This is why the term "numbers matching" is a worthless phrase. It does not mean the car has the original engine.

 

GM didn’t not add a EXTRA number to stamp pad .. someone has been in there and something is not right !! Check transmission # that will confirm should match vin number

 

It's a Turbo 400 trans. Where would I find the stamping?

 

It looks to me like the light numbers kinda match the original VIN. But someone maybe decked the engine and re-stamped it. But when they did, they royally screwed up and added an extra 4.

 

Looks like a 2 1 under the two 4's.....

 

There should be a metal plate attached to the passenger side of the tranny. If it is missing or appears to have been replaced, then the deception is complete. Sorry...

 

I think and hope Burning Brakes is correct. Here's the stamp with the paint removed.
It's definitely been restamped and believe the faint remnants of most of the original are still there.
Get out your magnifying glasses.

 

I’m not totally convinced it’s not a factory stamp. I’ve seen some very crazy St Louis vin stamps.

If it’s fake, then someone went through a great amount of effort to find the proper font stamps then screw it up really bad.

There are a handful of really experienced Corvette guys that might have some better insight but it will not matter as it will always be questioned because it’s fouled up.

 

I don’t know of many shops that can deck the block and leave those broach marks that look very similar to those left by the type of machine GM used originally. Aside from the few guys that actually have the same machine who do fake stamps but they would never do a stamp that looked like that. That’s why I think it’s possible that at St.L the vin stamp was misstruck too lightly then they went back and restamped the 18S then maybe rehit the rest of the numbers after they switched out the numbers for some other cars further screwing it up and added the 2 to complete the massacre. Hard to prove it, if ever, but there are some very funky real stampings out there.

 

...I was thinking along those same lines too. What if this a "factory repair" engine that made it back onto the line and GM restamped it when it went into another car?
Almost looks like the other stamp may have said 11321 . So, what if the engine failed at the plant and engine was repaired and used for car 23242 ?

...would be interesting to get the cast date off of this motor and see if it might align with car #11321 or 17321 date wise?

...wonder what Al Grenning would think of this one?

 

I’m with Ed and Paul… Those broach marks look perfect and the characters themselves don’t look bad either. There are a couple of things that I have questions about, but the two primary characteristics I check look good. The stamp underneath appears to be 42321 and is also incorrect, but might be the reason for the second stamp. This is not how the factory typically deals with a misstamped block so there is that to consider as well. I’d REALLY like to see the transmission stamp, that might shed some light on the issue!

In any case, I’m not quite ready to rule out this pad as a factory stamping.

Regards,

Stan Falenski

 

From what I see I believe this is a factory stamp. The broach marks are correct and so are the characters and the numbers.I have yet to see a restamped 68 motor that gets the 4's correct.

 

there is a metal plate on trans passenger side. If it is missing , sorry you have been taken for

 

Yes, and I thought of when you pointed that out to me about the 4’s on 68’s some time ago. Very interesting.

 

Factory stamps were done with a "gang" stamp. Even if the numbers were wrong, they would be aligned properly. That stamp was done by some shop after they decked the block....which may [or may not] have been done intentionally to put a re-stamp on it to match the vehicle.

Whoever did it failed miserably.

 

Not necessarily true when they made corrections. I have seen engine stamps that Al G has, in his opinion, stated are original that have had numbers initially transposed by mistake. They were then corrected on the assembly line by using single number strikes OVER the original stamped numbers outside of a gang holder. I just don’t see a engine rebuild shop having a broach machine deck a block like that, then having the proper fonts only to make a mistake like that and leaving it. They obviously used a gang holder on the stamp originally, and then only after the mistake made single and then partial strikes to correct it. But that is pretty much what a big factory would do as a quick fix and not worrying about how bad it looked as that is not a concern they would have. Only a restamper would worry about what it looked like.

On occasion you would see grind outs and of course they also get questioned and scrutiny. This stamp will get the same treatment forever but I am curious what the opinions of some of the other very experienced engine judges think. If the last digit was a 1 and then the stamper on the line forgot to change the next stamp to a 2, a result like this may happen. He may have realized as he was about to stamp it and did a light hit the first time, which is what it looks like. They would not need to grind out the entire vin number.

And then again, you could be correct and it could be a shop restamp. It’s just not obvious because of the perfect looking broach marks and correct fonts. This is one for the database with a special notation.