Mystery 396 casting date

[mr396]

That 68 calendar is cool It was right after the long 4th of july weekend I agree it was just human error.Thanks for every ones input.

[JohnZ]

Most likely a factory error, either in the casting date tag or in the setup of the gang-stamp holder.

The casting date tag was brass, with the individual characters soldered to the tag, then attached with screws to the pattern; when the (sand) mold was created from the pattern, the characters appeared as raised. There were multiple patterns for the same casting (each of which had their own pattern number for traceability), and they might have missed a date change on one of the multiple patterns.

Photos below of typical casting number/date/pattern number tags, and of a Tonawanda pad-stamp gang-holder.

[mr396]

Thank you JohnZ, That is very interesting. I never seen those before, That is so cool a picture says a thousand words. Do you know how long it took from casting to assembly and stamping at the tonowanda plant?

[JohnZ]

From casting to machining/assembly could be as little as one day to a couple of weeks; the Tonawanda foundry was right next door, on the same site with the engine plant. They produced 5500-6000 engines per day, just like Flint V-8 did (except Flint V-8 only made small-blocks - Tonawanda made both SB's and BB's).

[JChlupsa]

John,

Mahalo for the pictures and how they were used. Can you also tell how the screws that held them into place were used. Flat head verses Philps head. I have seen some with both being Flat head and others with one flat and one philips heads. I want to say i was told once that it was the difference in the shifts.

[TimG]

Wow....what an interesting block with an assembaly date before the casting date. This is one for the "strange but true" book. I've seen many small blocks with a one day spread, but it is more rare with a big block. I would think this one was built early in the shift before the error was noticed. I certainly like it and would not hesitate to advertise this error. I think that some strange things like this make for an interesting car.

[mr396]

Thanks, I agree. My wife says it like a mis-stamped coin. This camaro was a special order car and built late in the year (07C). the a/c compressor has a date of 7/10 same as the block, seems like chevrolet was making the parts for this car as they were building it. It was placed in service the same week it was built 07C july 21 1968. It was sold thru rosenthal Chevrolet in Virginia and ordered by Jack Popejoy. 11 days after the engine was cast, It was in the orginal's hands. Is that the normal time frame?

[TimG]

Do you have the warranty plate? If so, what date is on this?

[mr396]

The same date.

[TimG]

Good work, I love it..............