I found this article by a Mr. John Hinkley, a retired GM employee with many years of experience in GM production and assemby, to be very interesting. It illustrates in great detail the assembly line process at the Van Nuys and Norwood assembly plants specifically for the 67-69 Camaro but the procedures and process would probably be representative of GM assembly in general and provides some insight into the process that was used to build our Late Great cars . This is from the CRG (Camaro Research Group) website which is an excellent source of info on Camaros.
http://www.camaros.org/assemblyprocess.shtml
http://www.camaros.org/assemblyprocess.shtml