Utilizing the durable and dependable High Energy Ignition (HEI) system pioneered by GM these distributors avoid the unsightly wiring of stock Ford electronic ignition systems by installing this one-piece distributor with an internally positioned coil and module. Easy to install: just connect one 12-volt hot wire to the distributor (has optional tach hook-up). These units offer calibrated advance curves that are optimized for maximum combustion efficiency and for the elimination of detonation damage and throttle ping. Assembled from precision-madeparts for advance curve smoothness. Offers longer term durability and a higher voltage spark that permits a bigger spark plug gap resulting in more power and reduced plug fouling. Each unit includes a high-power coil a premium hi-dielectric cap with brass terminals and a low-saturation ignition module. By eliminating the stock-Ford ballast resistor more ignition voltage results in improved spark. Incorporates easily found High Energy Ignition (HEI) replacement parts. Assembled with upper and lower bushings (stock Ford distributors have only a single bushing). Technical Note: Gear not compatible with roller cams. If using roller cams please contact the cam manufacturer for proper gear selection.