In the beginning, stock actually meant stock. Back in the day, the key to successful moonshine running was to hop up your Plymouth or your Ford V-8, but keep it as stock-looking as possible, so the cops don’t think twice—the original “sleeper” car. But Prohibition ended, and these moonshiners took to racing each other, legally, on dirt. Whenever they could.
This is a companion discussion topic for the original entry at https://www.hagerty.com/articles-videos/articles/2018/09/26/the-life-and-death-of-the-stock-car