Hi Dave - Nope...not as far as deciphering the codes. My plan is to duplicate the data/fonts on rubber stamps based on the myopic info available....then be prepared to change/correct it if new info becomes available.

Pictures of similar plugs at http://www.1970z28camaro.com/engine/ along with pictures of carb stamps.

Thanks for the update.

Those are on I bet just about every GM Holley from that era. I wonder if the NCRS-Corvette guys know? Maybe not what they are supposed to be on each car, but at least what they mean.

"Pictures of similar plugs at http://www.1970z28camaro.com/engine/ along with pictures of carb stamps."

Yup, very well known site and that car remains a benchmark for Van Nuys built 70 Zs. But, it is a TH400 car, so the carb is different than the 4555 4-speed Holley along with the stamps.

"I wonder if the NCRS-Corvette guys know?"

I still need to check with a friend that has some very good connections in the NCRS...thanks for the reminder :)

Holley Carb Ink Stamp decode
 

I believe the ink stamp codes on the bowls are for either the bowl or bowl/float assembly codes for manufacturing use on assembly. I have seen the same codes for different year carb bowls, so it would rule out a DATE code. The same goes for the vacuum diaphragm, spring, and housing assembly. Just my opinion. Don.

Don - I tend to agree...just wish there was some document trail or evidence verify.

BTW, I spoke to my friend who has restored some nice mid-year Vettes and has been involved with the NCRS for years...basically, no clue, so maybe the ink stamp process was something implemented by Holley after '67??..maybe beginning '70? Not a lot of data points out there, so it's just speculation at this point.

The C3 NCRS guys don't know either... I have been all over the NCRS for the last 2 months researching my 71 LT1.

Thanks for the input James...not sure which direction I'll take on my 70Z project. Might reproduce the stamps and if new info comes to light at a later date, wipe them off with lacquer thinner and start over...

Steve,

Not sure if you are following this thread anymore, but more on this on the Camaros.org site:

http://www.camaros.org/forum/index.php?topic=19212.15

Thanks Dave...no, I had not seen that thread. Unfortunately, there is no discussion on decoding the stamps....just find the correct font, which is, in itself, an excellent step forward :)