HEI Ignition Coils

I will try to help. I never try on car first. I make distributor simulator with a couple uC pins, or use drill to spin distributor, and use timing light, scope and other instruments to view and insure correctness.

The module should control dwell in an analog way. At higher RPM, spark duration is cut back, the inductance of coil stores left over energy, next charge takes less time. A coil with full charge can put out a spark for 2+ ms. At 0.25 ms spark duration, a spark 5x longer than MSD CDI, it is easy to recharge in alloted time.