The date on the body tag represents the release week for the build order at Fisher Body. At best, it is only a general indicator of a car’s final assembly date.
There were two separate assembly plants involved. Fisher built the complete painted/trimmed body assembly, transferred it to Chevrolet final assembly.
Assembled bodies from Fisher were assigned a serial number just after they entered the body bank. At that time a confidential serial number [ex. 9N501234] was stamped into the body at two locations. The VIN tag was not attached at this time. Bodies were then shuffled into six queue lanes based on labor content. They were not final assembled in serial number order; the last VIN of the month logged by Chevy may be higher than the car behind it. When the last VIN of the month was logged is not certain. For this discussion, I assume it was Friday March 28. Manufacturing production calendars did not always follow Julian calendar format.
John Z has stated the production rate at NOR was 57 units/hour; 912 per day. At that time, Firebird production had not started but preparations were in process, seems to have limited output. March consisted of four weeks, Monday March 3 – Friday March 28. During that period VINs 607165 – 622674 were final assembled; 15,509 units an average of 775 per day. I’m assuming no Saturdays. Order release at Fisher Body had to lead final assembly by about 3 days; assume they released 775 orders per day at Fisher. So 03D was likely March 17 – March 21. When the next week’s order release began, there were plenty of the previous weeks order releases in queue. There was no 03C so those were 03B. Production orders are routinely pulled in/pushed out so the earliest 03D final assembly was March 21, mixed with 03B units. Conversely, the earliest 03E final assemblies are March 31, mixed with 03D units. The latest 03D final assembly I know of is N6240xx, final assembled April 1st.
Not usually this wordy. -6° here, not going anywhere.
http://www.camaros.org/assemblyprocess.shtml