The Belvedere replaced the Cranbrook as the top-line offering for 1954. Now, a separate model instead of just a two-door hardtop coupe, a buyer could choose a convertible, two-door station wagon, four-door sedan or the aforementioned two-door hardtop, now called the Sport Coupe. Slight styling updates adorned the carry-over body design. For the first time, small chrome tailfins appeared on the rear fenders. In March 1954, Plymouth finally offered a fully automatic transmission, the Chrysler Corporation's well-regarded PowerFlite 2-speed. Also new was a larger standard engine: a 230.2 in3 six-cylinder borrowed from the Dodge Division. Power was now rated at 110 hp (82 kW). Belvedere production slipped to 32,492 for the year.
Source: Wikipedia, 2013