No relay. 12ga wire. Where is all this crazy stuff coming from? It's just an HEI. There is no stress on the ignition switch and no need for big wire. Are you guys confusing an HEI with a new starter?
Crazy, eh? Interesting comment. I'm sitting here with a fried ignition switch that was made long before 1980 and only rated for 15 amps. I'll bet there are quite a few of them still out there. A 12 ga wire might be suitable. I'd prefer the margin of 10 ga, however. But rest assured the 15 amp ignition switch was the weakest link in this circuit, I didn't feel smart for overlooking something this basic, a relay would have meant that switch would still be ok and it failed because of the extra load. The amperage rating of that switch wasn't put there as a suggestion. So let's not be telling anyone here an overload on their ignition switch won't make any difference. That's not correct and it isn't prudent. Exceeding the amperage rating of any switch can cause premature failure and could even cause a fire since there is no fuse protection.
