I've never read a study on how long an OEM coil and ecu will run on 12v but it's indisputable that they were designed to run on 9v to provide better starting characteristics. Run any electrical device with more volts than it was designed for and it will work, how long would come down to how much of a safety factor was built into the original design.


70 Sport Fury
68 Charger
69 Coronet
72 RR