66 dart 225. converted to HEI, NOS dual field alt, NOS recurved Elec distributor, new NGK plugs, new Wires, new Cap, new Rotor. Recently Lashed, Super Six setup with Carter BBD which has been rebuilt. Timed to 18 BTDC, (with vac plugged). Curb idle at 850. Drops to 625 when put in gear. Ok so I am getting a sporadic miss when I am in gear, stopped at a light. I have a volt meter installed in the dash (digital) and it shows a 1 volt drop when I hear the miss happen. It is a very quick miss/drop. Like it will hover around 14.3, then all of a sudden drop to 13 when the miss occurs. Also when I say Miss, I mean does not fire. I do not mean a backfire. If I put the car into neutral rpms go up to 825 and there is no missing. So why do I see a voltage drop when the miss happens? Can this be caused from a bad eCoil?The eCoil is used from junkyard. Could it be caused from the HEI Module? Any ideas what to troubleshoot? thanks for any help.