67 - Tank Sticker versus Body Build Date Question

[Douglas L.]

What is the relationship between the "expected date of production" as shown on the 67 tank stickers versus the body build date as shown on the 67 trim tags? Here are three documented examples:

67 - 427 - Body build date: 8/31/66 - Tank Sticker Expected date of production: 9/14/66 - St. Louis
67 - 427 - Body build date: 9/16/66 - Tank Sticker Expected date of production: 9/30/66 - St. Louis
67 - 427 - Body build date: 3/03/67 - Tank Sticker Expected date of production: 3/03/67 - St. Louis
67 - 327 - Body build date: 2/16/67 - Tank Sticker Expected date of production: 3/03/67 - A.O. Smith

It appears from the above examples the time difference between the body build date and the expected date of production could vary by as much as two weeks and then at other times be the same. Was there flux in the time period between body build date and expected date of production or is there a time period that would be considered normal?

[Robert G.]

Re: 67 - Tank Sticker versus Body Build Date Question

What is the relationship between the "expected date of production" as shown on the 67 tank stickers versus the body build date as shown on the 67 trim tags? Here are three documented examples:

67 - 427 - Body build date: 8/31/66 - Tank Sticker Expected date of production: 9/14/66 - St. Louis
67 - 427 - Body build date: 9/16/66 - Tank Sticker Expected date of production: 9/30/66 - St. Louis
67 - 427 - Body build date: 3/03/67 - Tank Sticker Expected date of production: 3/03/67 - St. Louis
67 - 327 - Body build date: 2/16/67 - Tank Sticker Expected date of production: 3/03/67 - A.O. Smith

It appears from the above examples the time difference between the body build date and the expected date of production could vary by as much as two weeks and then at other times be the same. Was there flux in the time period between body build date and expected date of production or is there a time period that would be considered normal?

I would be highly suspicious of any expected date of production before 9/30/66, so the first one raises a red flag for me. I keep track of data like this but I don't have any easy way to cross reference what you're asking for. I would say there is no relationship between body build date and EDP.
A better thing to compare is VIN and EDP or Body build date and VIN.
I keep track of VIN/EDP and can tell you that there is a spread of thousands of vins that share the same EDP.

[Patrick T.]

Re: 67 - Tank Sticker versus Body Build Date Question

Here is the tank sticker for my '67 L-79. The expected date of production in 6-30-67. The VIN is 22526, so it is a very late '67.

[John D.]

Re: 67 - Tank Sticker versus Body Build Date Question

Wasn't there a strike In St. Louis on the september-october 1966 timeframe ?

[Wayne M.]

Re: 67 - Tank Sticker versus Body Build Date Question

With the exception of your first car in the list, with EDP 9/14/66, all 3 others have EDP's that fall on a Friday, including Patrick's example. Apparently this was the rule; maybe John H. knows why.

[Leif A.]

Re: 67 - Tank Sticker versus Body Build Date Question

Here is the tank sticker for my '67 L-79. The expected date of production in 6-30-67. The VIN is 22526, so it is a very late '67.

I guess I'm easily amused but I always get a kick out of the A82 option on '67 Corvettes - Headrests Bench Seat

[Larry M.]

Re: 67 - Tank Sticker versus Body Build Date Question

With the exception of your first car in the list, with EDP 9/14/66, all 3 others have EDP's that fall on a Friday, including Patrick's example. Apparently this was the rule; maybe John H. knows why.

Wayne:

I believe that all 1967 tank stickers have an Estimated Production Date (EPD) that is a Friday. That was one way of finding reproduction or fraudulent tank stickers in the early years. Now just about everyone knows that. I guess back then they couldn't estimate production any tighter than a week or so. The time between the Order Date and the EPD was typically around 6 weeks, if I remember correctly.

IN GENERAL, the actual build date of the car is +/- about 2 weeks (or so) from this EPD. Some cars are earlier than the EPD, but many are later. A few hit the date exactly. Special options (like headrests or tele steering, etc can cause the actual build date to be much later than the EPD due to unavailability of these parts at that specific time.

Obviously, production work stoppages (strikes) can also play a part in all of this…….and some of that did occur late in 1966.

The body build date is another issue. Generally speaking, St Louis built bodies became a finished car on the same day or 1-2 days later (weekend/holiday issues) than the day the body was finished. AOS built bodies became a finished car about 7-14 days after the body was built. This is due to rail transportation time from AOS to St Louis.

All my statements above are for the 1967 model year only. I do not have information for the other (later) C3 years. Take it for what it's worth.

Larry

[John H.]

Re: 67 - Tank Sticker versus Body Build Date Question

Cars weren't built until the material (parts) required for that particular car were in-house or reliably in-transit. When the plant accepted the dealer order for production, they assigned the Ident Number and the EDP; the EDP was simply a projection of 4 weeks (give or take a week or two) to procure and receive the material, which was ordered in 500-unit schedule blocks. When that schedule's material was on hand, Production Control configured that 500-unit schedule to fit their needs and released it to the production floor.

[Michael J.]

Re: 67 - Tank Sticker versus Body Build Date Question

You learn something new every day, never knew about the projections and Friday EDP before, fits with my tank sticker too.

[Harry S.]

Re: 67 - Tank Sticker versus Body Build Date Question

John's answer fits earlier C2's. My 63 EDP was Friday 4/26/63. The actual build date was Saturday 4/20/63. Well it was probably second shift of 4/19/63 just after midnight making it Saturday.

[David H.]

Re: 67 - Tank Sticker versus Body Build Date Question

Wayne:
... All my statements above are for the 1967 model year only. I do not have information for the other (later) C3 years. Take it for what it's worth.

Larry

FWIW: my 1980 has a trim tag date of 1 April (yes, I know April Fools!), with a DATE of 2 April (Wednesday) on the tank build sheet. The Shipper Document as well, shows both the "Invoiced Date" and the "Shipped Date" as 2 April. At some point the default Friday EPDs changed.

[Douglas L.]

Re: 67 - Tank Sticker versus Body Build Date Question

John,

So, a question for you. On car one below, the "order date" was 7/21/66 which fits what you say about the window of time between the order date and the EDOP. However, on the third car below, the "order date" was 10/13/66 and the EDOP was not until 3/3/67. Could a car get held up being produced for lack of a "particular" part so that it would push the EDOP out that far? Car #3 is a California A.I.R. car which represented about 11% of production.

67 - 427 - Body build date: 8/31/66 - Tank Sticker Expected date of production: 9/14/66 - St. Louis - Order Date: 7/21/66
67 - 427 - Body build date: 9/16/66 - Tank Sticker Expected date of production: 9/30/66 - St. Louis
67 - 427 - Body build date: 3/03/67 - Tank Sticker Expected date of production: 3/03/67 - St. Louis - Order Date: 10/13/66
67 - 327 - Body build date: 2/16/67 - Tank Sticker Expected date of production: 3/03/67 - A.O. Smith - Order Date: 2/2/67

[John H.]

Re: 67 - Tank Sticker versus Body Build Date Question

John,

So, a question for you. On car one below, the "order date" was 7/21/66 which fits what you say about the window of time between the order date and the EDOP. However, on the third car below, the "order date" was 10/13/66 and the EDOP was not until 3/3/67. Could a car get held up being produced for lack of a "particular" part so that it would push the EDOP out that far? Car #3 is a California A.I.R. car which represented about 11% of production.

Doug -

Yes, any number of things could push the EDOP further down the calendar, from a change in the dealer order to an incompatible option combination the Zone order edit didn't catch, to the dealer going out of trust with GMAC, to the dealer exceeding his order allocation, to a supplier part shortage, to a transportation failure, etc. There were lots of reasons why cars didn't get built as originally projected.

[Tom R.]

Re: 67 - Tank Sticker versus Body Build Date Question

FWIW: my 1980 has a trim tag date of 1 April (yes, I know April Fools!), with a DATE of 2 April (Wednesday) on the tank build sheet. The Shipper Document as well, shows both the "Invoiced Date" and the "Shipped Date" as 2 April. At some point the default Friday EPDs changed.

Not to hijack the original discussion thread but a number of practices changed how information was used by the late 1970s and/or late model C3s from the early C3s or the late 1960s. The intent of the EDOP, set by Zone, was to inform the dealer of the expected date when production would begin and notify the plant of an order. Changes included:

1. General Motors Acceptance Division took over management of the Corvette plant in the early 1970s.
2. This resulted in the GMAD landscape buildsheet adopted in 1973, accompanied with greater attention to production data driving assembly process
3. During the late to mid 1970s, greater attention to engineering process incorporated into the production process
4. Dramatic production increases from less than 30k units to nearly 50k units required more efficient processes to be instituted

I just posted this in a recent forum discussion but this table illustrates the differentials between pairs of VINs versus their associated EDOP, taken from the buildsheet and associated job number. The data is based on 1978 Pace Cars where data is plentiful to study the association between numbers. By 1978, the plant was using projected schedule data. Schedule data incorporated the EDOP and the job number and the schedule number. It shows assignment of VIN tags on contrast to the EDOP, documented from the build sheet.

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