are these plugs a good plug to run on a cheater plate with a .055n/.045f at 5psi,timing 30 total .ngk r5671a-7 or r5671a-8.motor is a dodge 340,9.8 compression iron head.currently running champion rc9yc at .025 gap.
We us the Ngk in my sons magnum 360 but we use -9 , watch the heat on the straps. Better to use a colder plug if possible
