Welcome to the Team Lee!
I have no idea. Though I'll bet Alan Colvin can answer that question in one of his five "Chevrolet by the Numbers" books. He has one book that is just about the Corvette model (all of them) and the other four books cover all of the other Chevrolet models made broken out by years of production (1955-'59, 1960-'64, 1965-'69, and 1970-'75). They make riveting reading if you have an interest in numbers, and are considered to be the defacto bible of authentication of any model car made by Chevrolet.