Dsandine

tried searching, couldn't find the answers I was looking for. I have the performance distributors screamon demon kit that comes with wires, cap and rotor and coil. I also bought basic champion copper sparks plugs to run with it. My question is, the stock gap for spark plugs is .035, but in the kit it says to gap to .065. Does anyone have experience with this, is gapping to .065 a good idea or should I jst use kit with stock gap of .035?

Thanks in advance for any guidance

JeepingDan

Higher voltage longer spark. Makes sense sounds like it won't miss a beat. If that's what they recommend then try it. Whats the worst? You pull the plugs and re-gap them.

country_boy454

I'm running this kit on my 5.2 ZJ and gapped them to .065". I would recommend getting one heat range cooler plugs. Using the stock replacement plugs I had issues with them burning too hot(pre-ignition). May be different on the 4.0s though.

Dsandine

I am currently running champion copper rc12lyc, just installed them and screamin demon coil today, I am going to pull them out in a couple days and check for signs of pre-ignition, if there is evidence of pre-ignition do you think champion copper plugs rc9yc will be cold enough?