The Ford F-550 was a variant of the 1st Gen F-Series Super Duty that was introduced for the 1999 model year. The F-550 Super Duty was a heavy-duty truck that was only built in a cab-chassis body style, in standard, extended, and crew cab configurations. Depending on the customers needs, these cab-chassis could be fitted with a range of attachments, even including pickup beds. The standard gasoline engine was the 6.8L V10, but there was also a diesel option. Initially, a 7.3L 'Powerstroke' V8 was the diesel option, but from 2003 onwards, a 6.0L 'Powerstroke' V8 was the diesel powerplant. Manual or automatic transmissions were available, as was rear or all wheel drive, with dual rear wheels. Production of the 1st Gen F-550 ended in 2007, when it was replaced by the 2nd Gen Ford F-550 Super Duty.