The Chrysler 300 "letter series" are high-performance personal luxury cars that were built by Chrysler in the U.S. from 1955 to 1965. After the initial year, which was named C-300 for its standard 300 hp (220 kW) V8 engine, the 1956 cars were designated 300B. Successive model years were given the next letter of the alphabet as a suffix (skipping "i"), reaching the 300L by 1965, after which the model sequence was discontinued.
The 300 "letter series" cars were among the vehicles that focused on performance built by domestic U.S. manufacturers after World War II, and thus can be considered one of the muscle car's ancestors, though full-sized and more expensive.
The automaker began using the 300 designations again for performance-luxury sedans, using the 300M nameplate from 1999 to 2004, and expanding the 300 series with a new V8-powered 300C, the top model of a new Chrysler 300 line, a new rear-wheel drive car launched in 2004 for the 2005 model year. Unlike the first "letter series" series, the successive variants do not feature standard engines producing at least 300 hp (224 kW), except for Chrysler's current top-line 300C models.
The 1960 300F introduced a new 413 cu in (6.8 L) Wedge engine delivering 375 hp (280 kW) in standard form. To boost power at lower and mid rpms, a special "cross-ram" intake manifold was derived. Instead of the normal V8 engine central intake manifold with carburetor(s) on top, the cross-ram consisted of two pairs of 30 in (760 mm) long tuned pipes that criss-crossed so that each set fed the opposite side of the engine. The carburetors and air cleaners hung off the sides of the engine over the fender wells. These long tubes were tuned so that resonances in the column of air helped force air into the cylinders at those engine speeds. Also new were four individual, leather bucket seats with a full length console from dash to rear seatback. Swivelling front seats were fitted as standard equipment.
A special 400 hp (300 kW) "short ram" version was produced for competition; in this, the tuned portion of the stacks was only 15 in (380 mm) long (though the overall tube length remained at 30"), so that the resonant effect was produced at higher engine speeds. Only 15 "short ram" cars were produced; these were also fitted with the exotic but often troublesome French Pont-a-Mousson 4-speed manual transmissions developed for the Chrysler-powered Facel Vega. Approximately 4 of these "Special GTs" are known to exist, including one convertible and one with air conditioning; it is believed that 15 were originally produced.
The bodywork was also redone for 1960, using Chrysler's new lightweight unibody construction and given sharper-edged styling with outward-tilting fins that were visually separated from sides. The "toilet seat" trunk lid contributed to a demeaning opinion of the 300F and was done away with after this one year of production.
Sales increased to 969 coupes and 248 convertibles.