1966 Ford Bronco U13 Roadster
Of the three body styles Ford offered when the Bronco debuted in the fall of 1965, the U13 Roadster was the most stripped-down and the rarest. It came standard with no roof and no doors (only cutouts for entry), a fold-flat windshield, and an open cargo bed behind a steel bulkhead.
A canvas-backed vinyl top and steel doors were available as options, but the base configuration was as open-air as it got. Standard 1966 interior trim was silver-gray, and Ford did not offer interior color choices that year.
Under the hood, early production cars carried a 170 CI inline-six rated at 105 horsepower. A 289 CI V-8 was added in March 1966 and was rated at 200 horsepower.
Both engines backed to a three-speed column-shift manual and a Dana 20 transfer case with selectable four-wheel drive.
Ford built 5,000 U13 Roadsters across three model years (4,090 in 1966, 698 in 1967, and 212 in 1968), against total first-generation Bronco production of 225,585. Fewer than 200 are believed to survive today.
Source