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We're doing a mechanical restoration on our 72 and have the drive train (engine, transmission, front end, rear end, exhaust) completely off the car. There are chalk marks low on the fire wall - have 009 NC (or AC, or DC) on the passenger side and P.B. (or P.D) on the drivers side. Just checking if anyone knows the history behind the assembly line chalk marks. thanks, Lenny
There are chalk marks low on the fire wall - have 009 NC (or AC, or DC) on the passenger side and P.B. (or P.D) on the drivers side. Just checking if anyone knows the history behind the assembly line chalk marks. thanks, Lenny
As bazza states:
assembly line gave the cars an individual sequential number, from presumably 001 to 999 then that got repeated
It was called the body number and was assigned as the body panels were built, assembled and then painted. Not all panels were painted together so it was important to track them until they came back together, given they were fitted as the body was assembled. T-tops, headlamp covers, etc were painted separately. I think in 72, a sheet metal panel protected the underbody panel so you have to look around it to see the body number.
Typically, the passenger side floorboard will have the body number in white or yellow grease pencil...model year dependent.
When the GMAD buildsheet was introduced (1973), it assigned the body number on the daily build schedule. In the later C3 years, a buildsheet schedule assignment will reconcile with that passenger side grease pencil number.
Hi Lenny,
I believe you'll find the numbering system, often referred to as the 'job number', went from 1 to 499, at which time it started over.
There was 'sometimes' a correlation between the car's 'sequence number' and the 'job number'.
As bazza and h4c have said.... in addition to the 'job number', other abbreviations for options the car was to have were written on the body too using something like a crayon.
An example of this would be a.c. since a car with air conditioning would require a modification to the firewall and a different configuration to the 'astro ventilation' system plenum under the rear deck grills. The a.c. marking alerted the production line workers to this.
Some folks are able to use these markings to determine how their car was originally equipped when it was assembled if they're unable to find the 'build sheet' that's been mentioned.
Regards,
Alans
A Build Sheet (1971)
Job number is 186.
186 written on 'toe board'.
Written in crayon below rear window on the rear deck... job number and R for 'radio'.
186 peeking out below the side of the shifter console.
This mark often survives because it's in the interior of the car.
Assembly line information
