Attributes . Caution! The DUI measures 14 in. from the hold down clamp to the top of the cap. The diameter of the distributor cap is 5.25 in.. Due to the height of the distributor, the big block DUI will not fit under some stock car hoods. The 1962 Plymouth, 1967 GTX, 1968 Coronet, 1969 Charger have been verified not to fit. Please measure for hood clearance on any automotive application. This unit will not clear Mopar Performance valve covers without modification to the covers. Distributor has instant timing knob. . Names