What's a Build Sheet?
This article references four terms used to describe the type of production documents commonly discovered today and includes tank sticker, build sheet, broadcast copy and manifest. Hobbyists probably adopted the terms tank sticker and build sheet because they literally describe the document type. The tank sticker got its name because it is found on the tank. Initially it was the Corvette Order Copy and later (post-1973) it became the manifest. While it's not known when GM introduced the term manifest in automotive assembly, the term is used interchangeable with broadcast sheet. Build sheets probably came into being to describe tank stickers not found on the gas tank and other production documents discovered as restorers began to take Corvettes apart for repair, restoration and maintenance.
Related C3 Documentation Differences
Ironically as data processing took a more prominent role in production, VIN assignment still took place on the factory floor identified by the contrast in font style that appears on the build sheet. On those build sheets studied the VIN is typed along with key codes using a manual typewriter. A small station was setup at the end of the paint booth where VIN was assigned, riveted to the driver's side windshield post and key codes assigned.
Once Key Codes and assigned VIN were typed onto the manifests they were distributed to each assembly line. It would not be until production moved to Bowling Green that VINs were pre-assigned (upstairs) before production began on the body.
The trim and body paint tag as a production document further underscores the point that 1968-72 production techniques differ from later C3 production. The trim tag station was moved some time during 1975-76 model year to accommodate the need for space to match the increase in production during the mid to late 70's. The station was moved between paint booth 1 and booth 2. As a result, body build tags for Corvettes built prior to 1975 were not painted while trim tags after 1975-76 was painted after the primer coat and first paint coat.
Not surprisingly a relationship exists between trim tags and build sheet. The build sheet lists RPO code for paint and interior referenced on the trim tag. It also populates the manifest with the broadcast codes for matching interior parts such as carpet, seat belts, steering wheel, steering column, and related trim.
What disappears from build sheets after 1973 is the scribbled reference to the three-digit Body Shop job number. The job number was assigned for a vehicle and body panels marked as they were prepared for assembly. This job number was also hand written on the Corvette Order Copy with the chassis copy glued to the gas tank. It appears that by the mid-seventies, this practice was discontinued. However, the job number was still used throughout C3 on body panels to track companion panels through the body shop.
Late model C3s should be the best-documented Corvette models among the first three generations, but much needs to be researched, studied, and documented. We know the application of processing engineering techniques took on a greater role in the mid-'70s and included the increased use of data processing to improve productivity while maintaining production costs.
The publication of this article hopefully will stir passion for discovery, discussion for teasing topics of personal interest, and publication of new information that will contribute to the body of knowledge for the late-model series of the third generation. Students of C3 production documents are encouraged to flip the traditional perspective180 degrees. Instead of peering forward from the 1968-72 production period, glance backward from Bowling Green production to the early methods of the St Louis assembly plant. Given this perspective, three distinctive periods can be arbitrarily outlined and used to set a course for study of C3 production documents. These periods are distinguished as:
1. 1968-72 evidenced by use of
a. Corvette Order Copy as the first tank sticker
c. Exception control letter codes
d. Body broadcast copy and a chassis broadcast copy
2. 1973-81 evidenced by the use of
a. The single page multi-copy manifest
b. Chassis copy of the manifest glued to the gas tank
c. More prominent use of broadcast codes
3. 1981-82 evidenced by
a. VIN assignment prior to body build,
b. Expanded use of data processing and first use of bar codes
c. Manifest copies saved and sold by the National Corvette Museum
Much can be learned from the study of late model production documents. Our knowledge of 1968-72 Corvette production documents must not allow us to fall into complacency but rather serve as a source of inspiration to search, study and document the balance of C3 production.