I currently run RC12YC Champion plugs in my naturally aspirated 540. I run the gap about .045 with a Crane HI-6 ignition. I'm adding a ProCharger and was wondering if these plugs would still be the preffered choice. Also does the gap change with the blower?
Any recommendations would be appreciated.
Thanks,
Dave

Normally you would make the gap smaller with a blower, but I am running the 45 gap, I have tried smaller & motor did not idle as good but ran the same on top. I am using the msd box. Ar far as temp range of plug you want a cold plug. I do not like the champion plug from problems I had years ago so I do not know how this plug is rated.

After playing around with several combos the NGK R-5673-8 with the gap at .035 seems to work perfect for me. 750 Hawks.

Kurt.

My dyno guy set plugs at .035 on my N/A 540

Tip: I have a Procharger M1, besides the noise it's great. But don't run it past 5K rpm (7 # boost) much, I blew mine at 5.5K rpm (~9 # boost at that rpm).