Special carriage bolt and locking nut used to mount clutch pedal stop (C2OZ-7A530-A) to the pedal support on manual transmission cars.
Fits:
1965 and 1966 Mustang
1962, 1963, 1964, and 1965 Fairlane
1960, 1961, 1962, 1963, 1964, and 1965 Falcon / Comet