N636709 could be an 05A body tag date. When the build order for the body was released at Fisher, the body tag was punched. Somewhere in the late April/early May time frame, a number of tags were stamped 04L. No idea why; maybe there was a reason. I believe they were all done at the same time; then the date revised to 05A. Having worked as a production planner, it is customary to have a queue of released orders to ensure uninterrupted production. Within the queue, some orders have higher priority. No question orders with 05A dates were released from the queue and produced prior to 04L orders.
As completed body assemblies were received at the body bank at Chevrolet final assembly, the last 6 digits of the VIN were assigned. Bodies were then assigned to one of 6 lines in the bank, based on assembly labor. Cars were not built in VIN order. Entirely possible some early N637xxx VINs were final-assembled prior to later N636xxx VINs.
Body tag date is at best, a rough approximation of final assembly. ZL1s #3-#39 have 02D tag dates; none of them were final-assembled in February. Our ’67 Z/28 project has an 06E tag date. The original engine is V0706MO. Car was final-assembled on or about July 12, 1967.
http://www.camaros.org/assemblyprocess.shtml