CNC machined billet aluminum housing is 3/8" smaller in diameter and 7/8 shorter than conventional Chevy V-8 distributors with the points type cap. Maintenance-free magnetic pickup and precision reluctor create stable trigger signals throughout the rpm range. Easy-to-adjust mechanical advance with supplied springs and stop bushings. Adjustable slip collar mounting flange for engines with modified deck heights. Polished steel shaft is QPQ coated and guided by a sealed ball bearing and extra long sintered bushing. Advance plate and weights are fine blanked from chrome moly steel and QPQ coated for friction reduction. Advance weight pins are staked and tig welded to the plate. Nylon pads ensure smooth operation of the advance weights. Mechanical advance assembly can be locked out for crank trigger systems. Special oil tract improves lubrication to the distributor and cam gear. O-ring seals can be added to modified blocks to improve oil pressure control. Must be used with an MSD 6, 7, 8, or 10 Series Ignition. Supplied with small diameter HEI style distributor cap and rotor (will accept 8441 Cap-A-Dapt). Will not accept a vacuum advance canister. No CARB Exemption Order Number.