What are my options (harmonic balancer)
Not exactly. It’s something than I learned from some much smarter slant six owners than I.
You can hook a gm style hei control module to a external gm hei coil (such as from a 98 1500 with v8) and to both wires of a hal style distributor, and you get hei ignition system for early mopar. Just need 12v and ground. Buying the Pertronix HEI 3 control module provides multi spark.
I will follow up with pictures and a link to where I got the information from. This is a great solution for many applications, and it’s universal, just needs a magnetic pick up.