The Ford F-350 was first introduced in 1953, the F-4 became the one-ton F-350. Prior to that, all Ford trucks were just single digit (F-1, F-2, F-3, etc.). The early (prior to 1953) Ford trucks were sold in eight different weight ratings, with pickup, panel truck, cab-over engine (COE), conventional truck, and school bus chassis body styles. The F-350 was available over the years with single or dual rear wheels, 2 or 4 doors. different engine & transmission combinations (including diesel engines). It was available from Ford as a chassis/cab so you could have an aftermarket body of your choice (ambulance, dump truck, ramp truck, rollback, stake bodied flatbed, tow truck/wrecker, etc.). It was available with 2 or 4 wheel drive.
