WHEN HORSEPOWER RAN FREE

THE HORSEPOWER WARS had been raging since Cadillac and Oldsmobile dropped OHV V-8s into their baseline models, but things really kicked off in 1955, when GM’s bread-and-butter divisions received their own homegrown V-8s. That year, Chrysler introduced a car named for its Hemi engine’s horsepower rating: 300. By 1957, some of the car companies were at least toying with fuel injection, and for 1958, a scant three years after the launch of the Chrysler 300, Mercury introduced its triple-two-barrel-carburetor Super Marauder V-8, optional across the Mercury line, and rated at 400 horsepower from 430 cubic inches. Granted, it was in a 4,300-pound Mercury. Even so, the gauntlet was thrown.

To some degree, engine sizes and power had to grow: Cars themselves were enlarging at a rapid rate. A 1955 Star Chief, Pontiac’s biggest V-8-powered car for the year, ran a 180-horse, 287-cube V-8, had a 124-inch wheelbase, was just over