Resistor VS non Resistor spark plugs
Yep, ngk and others don't make non res. racing plugs for no reason. Old Smokey used to believe in running no more than a .045 spark plug gap. His thinking was higher gaps in his test made no more power and best to keep the voltage lower.
Smokey also believe in high current sparks but said places like msd won't make a box with very high current since it could be deadly if a person got poke by touching a plug wire while the motor is running--like turning the dist by grasping the top of the dist. I'm guilty of doing that but try to wear a glove while doing it.
btw, I run .035 plug gaps. Am I losing out on 5hp, maybe. Does my motor run nice and smooth with no mis/crossfire, yep--even in the pouring rain.