I want to thank everyone who responded and apologize for not revisiting this thread earlier. What this wiring was has been solved! I was talking to an old time ex dealer mechanic and I asked him about the extra wiring. He said no, that the wiring had to hook up differently like hotrod lincoln said. He asked if I had some "unknown" relays on the firewall on the drivers side. I had those relays, I said. He told me that it was probably the TSC (Transmission Spark Control) harness and that it probably wasn't hooked to anything any more. TSC was an early emission control system that controlled vacuum advance, but it was still hooked to the hot side of the coil. The plug would fit a 10si alternator, but since there weren't any in '71, there was no problem with mistaking plugs. It just happened that the TSC harness ended up laying along the inside of the right hand rocker almost like the alternator harness! Anyway, it is all gone now and everything works fine. Strange, huh?
Best wishes,
Les
