[chopper]

FWIW, now that you've gotten the system working, it might be instructive to correct at least one error which popped up in this thread. Statements were made that the MSD system has to have at least 12 volts to work. If you check the MSD installation instructions, the 6-series units claim to deliver full performance at ignition voltage levels between 9 and 18 volts. This is not meant to be disagreeable with what the MSD tech told Mike; I'm just repeating what appears in their own installation manual, available online. 7-series are spec'd for 10 to 18 volts, again from their installation manual. They have to work at lower than 12 volts because of the aforementioned voltage drop during starting operations. Just included for future reference.