[CompClassics]

I actually just had a client that had a very similar problem with his 1972 Corvette with a Pertronix and a MSD Balaster 2 coil. Check your supply voltage to the coil (+) post when the engine is running, if the supply voltage is greater than 12.5V you may have found the problem (you should not have anything more than 12.5V). My client had recently replaced his alternator with a higher output unit, the supply voltage to his coil was greater than 14V causing the coil to overheat and fail. I figured out how much to reduce the voltage with resistors, installed a resistor assembly and he has not been left on the side of the road since.