There is not a bolt on HEI to 371 57' olds. but ther is those fancy looking rolls of wire + somekind of chip (god knows what) any experiece anyone? Not the Jimi kind of experience.. I saw a couple of L.A rodders installing somekind of special ignition system to 55' olds engine in a tv show.they said that it was an ol' school trick or something. Ring a bell??