I am working on my buddies 71 Demon, I built a 72 360 engine for it. I had it out 2 weeks ago, and it fouled all the Autolite spark plugs he had in it. It hafd a carburetor problem, so I put a known good carb on it, and a used set of NGK spark plugs that were one heat range colder. It is running fine now, but trying to source the correct NGK spark plugs has been a problem. All I can get are resistor plugs, and that is not what I prefer. It is a factory electronic distributor, old chrome box and old Mallory coil. Anyone use resistor plugs in place of non resistor ? Took me a week to get 8 spark plugs from my NAPA.