As several knowledgable people have said before, scheduling of the cars depended on availability of the parts necessary for building it, and it is logical to assume that one plant might have a specific part available when the other might not. They also gave priority to *sold* customer cars, as opposed to dealer orders for inventory. All things being equal, I'd suspect they built the cars in the nearest plant to the "need"... but all things are not always *equal*..
Gary W / 09C 69Z28-RS, 72 B 720 cowl console rosewood tint
69 Corvette convertible, silver/black 350 hp,
60 Corvette white/red, 72 Corvette coupe, '70 Mach I
90 ZR1 red/red #246, 90 ZR1 white/gray #2466
72 El Camino, '55-'56-'57 Nomads, '55-'57 B/A Sedan