Features:Billet housing is 5/8 smaller in diameter than stock Ford distributors; Must be used with an MSD Ignition Control; Supplied with small diameter cap with HEI style terminals and race rotor (will accept 8441 Cap-A-Dapt); Nylon pads ensure smooth operation of the advance weights; Advance weight pins are staked and tig welded to the plate; Mechanical advance assembly can be locked out for crank trigger systems; Advance plate and weights are fine blanked from chrome moly steel and QPQ coated for friction reduction; Polished steel shaft is QPQ coated and guided by a sealed ball bearing; Maintenance-free magnetic pickup and precision reluctor create stable trigger signals throughout the rpm range; CNC machined billet aluminum housing and billet aluminum base; Easy-to-adjust mechanical advance with supplied springs and stop bushings;