Birthday calculator

[Gregory G.]

Can someone tell me about what day my car was build.
Vin 94370S411364
eems the online calculator does not do my year.

Thanks

[John S.]

Re: Birthday calculator

Greg,

Your car was built on June 8, 1970.

[Tom L.]

Re: Birthday calculator

How did you calculate that? My car is #12305, 941 after Greg's and the trim tag lists the build date as June 15th, exactly one week after the date you listed. At 940+/- cars per week, GM would have built twice as many as they actually did. I'm assuming that the date on the trim tag is the build date. Is that correct?

[Rob M.]

Re: Birthday calculator

http://www.c3registry.org/index.php?job=BirthdayCalculator

[Jack H.]

Re: Birthday calculator

Date on the trim tag is the date the BODY subassy started its build. They spent a variable amount of time in the paint booth (how many cycles before QA/QC was happy and passed the car). That's why we go from the VIN number even though the body build date can be pretty darn close on many cars...

[Terry M.]

Re: Birthday calculator

All of the so-called birthday calculators are based on mathematical calculations using reported production numbers and ASSUMED number of work days or shifts per month.

Generally the reported production numbers are those reported by Chevrolet for a given month. Unfortunately the number of work days or shifts in a given month can change from what we might expect. The most variable is whether the plant worked between Christmas and New Years. How many Saturdays did they work in a given month? Some holidays were on a different schedule than today, and in a given year those holidays might have fallen on a weekend, Monday or Friday. What did that do the the number of days they worked that month?

Also different people give different meanings to the car's "birthday." Does it mean the date on the trim tag -- for those cars that have daily dated trim tags? Does it mean the day it left the assembly line? Or the day it left the plant for the parking lot out back? Or even a shipping date? Another question is when Chevrolet regarded the car as complete -- how did they count the monthly production? I have been told that over the life of the St. Louis plant the point at which the counters regarded the car complete changed. The term "birthday," without some definition, is almost as meaningless as "numbers matching."

For the OP's 1970 the trim tag should give him a good date for the body build. Usually adding a day or two (unless a weekend or holiday is involved) should give an APPROXIMATE off the end of the line date.

Are we having fun yet?

[Terry M.]

Re: Birthday calculator

For C2s and early C3s (without painted trim tags) the tag was installed after body paint, but before trim was added, and of course before the body met the frame.

Later C3s (and I am not sure when it started, and I don't want to guess) had painted trim tags and those tags were installed before the body was painted.

On C3s some of the labels were installed nearer the end of the line. The certification label on the driver's door was installed late in the assembly operation, but unfortunately this label shows only the month of production. This can create confusion when the trim tag shows one month and the certification label shows the month later.

[John H.]

Re: Birthday calculator

Terry -

In "steel" car plants, the "pay point" where the production count was registered (and the plant got paid for building the car) was at the end of the Final Line, where the car was driven off to toe-in and roll-test.

St. Louis was a bit different, as the car had no interior trim from the top of the doors down when it was driven off the line to toe-in and roll-test, as the next stop was water test, and the untrimmed interior made it easier to spot the source of any leaks (and to repair and re-test). Seats, carpets, door and quarter trim panels, shift and park brake consoles, jack boards, kickpads, etc. were installed after water test on the Final Trim Line; when the car came off the Final Trim Line, it was a "complete car", ready for Final Paint Repair and shipping.

When I was there in '67-'68, the end of the Final Line was the "pay point"; it may have changed in later years to the end of the Final Trim Line, depending on who was interpreting at what point it was "built".

[Terry M.]

Re: Birthday calculator

The information that I got came from George Barlos (sp?). I think he was referring to changes from C1 to later era, but when we were talking about that he wasn't clear exactly what time frame he was referring to. He simply made the statement that the point they counted it as a complete car changed over time.

[Gregory G.]

Re: Birthday calculator

Looks like you are right. My trim tag is June 5 just 3 days before the projected BD.

Thanks all
As alwasy very intersting.