I'm curious, is there any advantage to a old school "canister" style coil versus say an LS coil?
As for 6 volts, I was thinking of running everything off of 12 volts with a voltage reducer to drop from 18 volts to 12ish volts.
Slightly less likely to fry coils, fuel pumps and relays that way and everything is on the same voltage.
Or are you saying to run a 6 volt coil on 12 volts so you get a hotter spark than out of a 12 volt coil on 12 volts?
Aaron Z