I believe you are correct. I think he originally had two wires on that post but removed them when he put the HEI in. One wire to the coil. One resister wire to the ign. switch. His new pickup location was to supply voltage for "run" and "start". I think he may not getting it in the "start" part of the time or maybe not even at all. I think the 12v reading he is getting may actually be coming from the tach connection.
