Deep in the timberland of Vernonia, Oregon, inside a historic brick building that originally opened as a Chevrolet dealership in 1938, longtime collector Gary Myers guards a deceptively understated two-door pillared coupe. It was, when new, in fact, the cheapest big-block intermediate from the cheapest division of the smallest of the Detroit Big Three. If it weren’t for those obscenely big, black valve covers, it wouldn’t be such a big deal. How…