Capacitor Discharge (CD) Ignition?

The GM 8-pin HEI is simplest and best. It was in 1985-95 V-8 trucks. Grab the module (inside distributor), connector & wire to pickup, coil & cable to it, and cut the red & wht supply wires as long as you can. TrailBeast here sells as a kit. You can leave the 6-pin connector open, or use it for spark timing control (from Holley Commander 950 or such). The Megasquirt site has more info. A Mopar distributor pickup can trigger it, but you need the polarity right for most stable spark.