inefficient today to consider that GM was producing unique 455 Pontiacs, 455 Oldsmobiles, 455 Buicks, and 454 Chevrolets--four engines within 1 cubic inch of displacement--all at the same time.

As GM grew and flourished along with the U.S. auto industry in the middle of the 20th century, its divisions began building larger engines. Buick was the first automaker to use a V6 engine in a ...