Performance Distributor D.U.I. is a high performance, precision built ignition system that is capable of turning up to 10,000 RPM’s. That’s almost double the output of a stock H.E.I.! Modern technology and years of HEI engineering experience has allowed us to develop a high voltage coil, high dwell module and mechanical advance system that would turn the high rev’s needed for today’s racing engines. Racing H.E.I. Distributors Single-piece ignition delivers consistent, reliable performance up to 9,000 RPM. No other ignition box is needed. Distributor has aninternal racing coil and Dyna-Module for maximum spark energy and a customized advance curve. Distributors has a Locked Out Advance, non vacuum advance and has black cap. Please e-mail with questions.