Loancheetah

I recently had to change the alternator out and shortly after doing so it decided to start giving me a hard time.I had difficulty getting it started and then after a few miles the tach would start spiking and then the motor would stutter and leave me stranded shortly there after. I then replaced the coil and an ignition module located on the coil mount, this work for 2 days and then it began again.I was told that Chevy's use a ballast resistor limiting incoming coil voltage to 8 volts. Does anyone know if that is true?