-H.E.I.-, Tachometer Harness to GM H.E.I. (High Energy Ignition) style distributor, in-dash tachometer Note: Modified... see more-H.E.I.-, Tachometer Harness to GM H.E.I. (High Energy Ignition) style distributor, in-dash tachometer Note: Modified for use with a GM H.E.I. distributor