MSD engineers fit all of their high performance distributor experience into a special compact housing designed to be less obtrusive for Ford engines. The diameter of the special black cap and housing are 5/8" smaller than stock Ford distributors providing extra room in front of the engine. The new MSD Black Cap features Stainless Steel spark plug style terminals and is firmly screwed down to the housing. The distributor relies on MSD's race proven magnetic pickup and precision reluctor to deliver accurate trigger signals to the MSD Ignition throughout high rpm. The reluctor assembly is turned by a hardened steel shaft which rides in a sealed ball bearing for high rpm stability and endurance. Must be used with an MSD 6, 7 or 8-series ignition. Mounted to the top of this shaft is a fully adjustable mechanical advance assembly. The rate at which the chromoly assembly advances the timing is easily controlled by changing the supplied advance springs and stop bushing for total advance.