Question about VIN stampings

[Jeff H]

I was looking at some partial VIN stampings and it sure looks like the partial VIN on the engine is also the exact same stamp used on the hidden VIN's on the body. Is this a known fact? I know the transmission VIN and engine VIN should be the exact same stamp but I wasn't sure if the engine/trans stamp would match the hidden VIN as well.

[njsteve]

It is usually the same sequence. See the attached photo of a 72 Trans Am. It goes Year, Plant, Vin sequnce: "2N519898"

[retengw31]

I can help out a litle on Oldsmobiles built in Lansing plant from 1968-1973 when I was a process engineer on the final assembly line. Among many other things, VIN stamping on the frames was one of my responsibilities.

All the Olds cars built then were body/frame and the only hidden VIN stamps were on the top frame rails on the drivers side in two places. One was near the transmission crossmember and the other was behind the rear wheel. In each case, it was a 9 digit alphanumeric with the division (Olds was number 3), the year (8 for 68, etc.), the plant code (Lansing was M), and the 6 digit sequential number starting with 100000. This same number was hand stamped on the engine block and the transmission casing with a BFH. Only other place the VIN appeared in the car was on the VIN plate that was rivetted to the upper I/P and the blue sticker/label in the door jambs after 1970(I think).

I think that policy also applied to other GM divisions with body frame cars, not sure what they did on unibody and partial frame cars (like Camaro/Nova, etc.)

[Jeff H]

I know the sequence is the same but I'm wondering if they physically used the same gang stamp to hit all the areas that needed the partial VIN. So if there was something odd about one of the digits it would look exactly the same on all the stamps(ie they used an "I" instead of a "1"). So would they stamp the engine/trans and then hit the top of the cowl and firewall by the heater box all with the same stamp before changing the gang stamp for the next car?

[Lynn]

JohnZ could certainly give us a definitive answer on this, but I will go out on a limb and say the two body stamps were from the same unit. However, the partial VIN on engine and trans were a smaller font, so could not be the same. I want to say 3/16 on the body numbers and 1/8 on the engine/trans. I am almost certain JohnZ recently posted something about the body stampings on the team camaro site. It was a type of roll stamp and done by machine, not with a gang holder like engine and trans.

I just went out in the garage and looked at my body stampings and they appear identical, except the one under the blower fan is upside down. The fifth digit on mine is somewhat out of place about the same amount on both of mine.

Lynn

[Pacecarjeff]

The hidden body stamps are different then the engine and trans stamps.

The Engine and Transmission stamps should be identical to each other.
They were stamped by the same guy at the same time.

[njsteve]

I guess I misunderstood your initial question. While the alpha numeric information will be the same, the stamps that imprint them are definitely different in both size and font.

[COPO]

Is that true on all full frame cars, the body doesn't have hidden VINs and they are only on the frame as outlined in the post above by dehw31? I though Chevelles had hidden VINs on the body like Camaros.

[Keith Tedford]

The transmission and engine were done with the same hand stamp. The frame and firewall were done with the roller type stamp. The numbers were changed manually so sometimes numbers were installed upside down and "6" and "9" got mixed up along with whatever other mistakes that could be made. I maintained these units in the Oshawa truck plant for many years. Hand stamping the firewall with that many numbers would cave the sheet metal in and just would not work. The roller type stamps for the sheet metal could act up some times and not index properly but worked pretty well for the most part when properly maintained. Our Baltimore built '69 had no VIN numbers on the frame, just some frame manufacturer's numbers.

[SS427]

Charlie,
Full frame cars also have VIN's stamped on the frame and firewall. It depends on the plant and body style as to where they are found. Chevelles also have them stamped on the firewalls and frame though I seldom find any VIN stampings on Chevelle frames. Also, at least one plant routinely does not stamp the firewall on the Chevelle and stamps the VIN under the dash panel instead as I recently was informed.
Rick