Body Unit Number

Q: Body Unit Number

The number on the body tag (firewall) and the Fisher Unit number, how were these sequenced.

Also, how does the build date on the Body Tag correlate to the Billing date from GM? How long did it take to put the entire car together?

A: The Fisher Body Unit Number found on the Firewall Trim Tag was unique to each assay plant and was not a sequential number nor was it sequential with the VIN or any other number or build-date information.

The Unit Number was an internal Fisher Body Number used for sequencing the build of a vehicle relative to certain production factors such as color, model, options, etc.

Once the order was placed by a dealership, PMD routed this to the Plant for scheduling by the Broadcast Dept. That particular order was assigned for build according to the above factors and not necessarily in the order it was received.

If the same dealership ordered 2 different Firebirds on the same day, one a 6cyl verdoro green coupe and the other a Ram Air I black conv, chances are the coupe would be sequenced for build first. Both may have similar VINs but the Body Unit Number could vary quite a bit. Here’s an example:

VIN- 164250 Body Unit No.- 4886
VIN- 164279 Body Unit No.- 7679

The Build Date on the Trim Tag was assigned by Fisher Body when the Sequence Number was assigned and scheduled for build. This represents the Month/Week when the body began to take form in the body-shop (Body in White- BIW). Again, there are factors here that dictate how long it took for a Body in White to be fully assembled and roll off the Final Assy Line. Part availability, Drivetrain availability and color all factored in. Generally, it took less than a week from the time a body received it’s Trim Tag until it left Final and the Certification/Buy-Off Line. Once a vehicle was painted and transferred from the Fisher Body Facility to the Final Assy Plant, it generally only took a day to complete the car.

The Billing History Invoice Date was the date that the vehicle was “bought-off” after Final Assy. This is buy-off initiated the billing and delivery process. It’s not uncommon to find some vehicles with a few weeks between the Body Build Date and Invoice Date due to special orders (colors, engines, etc.).

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