Muscle machines Ford began flexing its Mustang muscle in 1964, and by 1967, it looked like the springtime yellow convertible parked along Duplainville Road near Duplainville, Wisconsin, on May 18, 1992. Passing in the background is a Wisconsin Central southbound roaring by with two General Motors (EMD) SD45s from the same era. Twenty-cylinder SD45 production ran 1965 to 1971, with these two manufactured right toward the end, built for the fledgling Burlington Northern. Nonetheless, both neatly represent a “muscle era” of American machines.
