I wanted to be clear about spark plugs for my truck in my signature

The STOCK plugs for my 351W are Champion RC12YC and these have a spark plug reach of 0.460.

I have Trick Flow heads and the paperwork with those heads say to use RC9YC. These have a 0.750 reach and I assume it's longer because of the larger heads.

Going with that, I think I should use an RC7YC which is just one stage cooler than the RC12YC because of my blower. Does this sound correct?

Also, these plugs don't have a resistor, which is what I prefer. But will that cause any problems with the electronics?

 

One heat range colder than stock is correct. I have Victor Jr heads on mine and all I use is NGK TR6 copper plugs.