Production numbers...where do they come from?

[William]

The only source for production figures is Chevrolet. Even the earliest production control systems included a feedback loop to compare planned production to actual, net out material requirements, schedule production, etc. At the end of a model run this system could produce a report listing production volume by option; John De Lorean alludes to it in his 1974 book. While Chevrolet needed to know how many LS6 engines or AM/FM radios it sold, it didn't need to know how many went into coupes, El Caminos or convertibles. This would require reporting combinations of options, a nearly impossible task given the number of options available and vehicles produced. De Lorean stated for 1969 Chevrolet could have produced one million cars without building 2 exactly alike.

When you see a car featuring a rare combo of options with a production figure it is generally puffery, intended to enhance collectibility/value of the car. No one knows how many 396 Z11s, Z/28-RS or LS-6 Chevelle convertibles were built. You'll see the occasional "statistical analysis" applied to option combos. These produce opinion, not fact.