18v ignition question

[3kstreeter]

Has anyone ran 18 volts with an hei ignition? I know this idea is nothing new but i dont know anyone that has actually tried it.
Just looking for some basic stuff like how did you wire it or if you have dynoed with it. Plug gaps and how many jet sizes need to be increased. I see that there is a mini vip 18v step up box but i dont know of anyone that tried that either.
I was thinking the easiest way would just be to use a small 6v battery with my 12v. I just need to know what are some things to keep in mind if i do try this.

Thanks in advance

[setup479point2]

Have used the Speedway 17v box . Plug gap at .045 , no changes to anything else . The good thing is even if battery drops to 10v you are still getting 15+ to the ignition . If you are in IMCA land I don't think its legal . Here most of our cars are on 16v battery system , again don't think that is legal in IMCA . I might be wrong on that . 16v is really the way to go if you can , cars start better , and even if some charge is lost you still have 13v or 14v.