We're big fans of the HEI because it's simple and reliable. The Performance Distributors Racing DUI distributor packs a fierce punch with its Dyna-Module and racing coil; the manufacturer even suggests a plug gap of 0.055 inch, which maxes the power and prevents plug fouling. This model features DUI's instant timing knob (seen just behind the valve cover). One half-turn clockwise equals 1 less degree of timing-no timing light or wrenches needed! Check out the locking thumbwheel at the base, which prevents vibration from altering the setting.