It makes me wonder. There are probably some sales stats floating around the Internet. I remember a lot of six cylinder full size Chevys from that era. In fact I knew my grandfather had a green 1963 Belair sedan. I never thought about the drivetrain. Not long ago my aunt was cleaning out some of my grandparents old papers (my grandmother saved everything!) and she gave me some letters that my father sent to them when he was in Viet Nam in 1962. He was trying to persuade my grandfather to buy a V8 / automatic car, since he was hell bent on buying the cheapest 6 cylinder 3 speed one on the lot. My father and grandparents are all long gone, so I asked my aunt and she said yes, the Chevy was a 6 cylinder 3 speed, she had to learn to drive in it in the city. She hated that car!