[RichardJ]

I have used a paper match book myself. Out on damp night and the engine starts spitting and with nothing but pen knife. Match books used to be easy to find along the side of the road.
I put a HEI in my 67 back around 1990. Freshly divorced, it was the only thing running that I could afford to Insure and I was driving a good distance to work. Changing or cleaning/adjusting the points every two months was getting old.
No other reason to make the change.

For 33 years that coil in cap HEI and the 15 year ago external coil HEI have been running with the ballast resistor still in place.

14 V at the battery and 12 V at the HEI, thank you very much.