I have a procharged intercooled,carbed hp 500 and need to buy a couple sets of spark plugs it had ngk v power plugs r5674-7 that plug looks like it would be to hot to me but im new to the super charger stuff.any body run that plug with a procharger? I was thinking a little cooler plug like a -8 would be better for this application?

#8@ .035

I run B8EFS blown alu head this is a long thread tapered seat non projected tip gaped at 40 work fine. I think the steel heads use the short threads better to be on the cold side on your plugs.

steel heads?? if so i have ran ac mr43t. alum heads ngk r5671a-8 or r5672-8 all worked great also this is not my advice it came from Kieth eickert when he built my motors..

@.040 there is a chance of blowing the spark out. >035 is safer

yes steel heads.so i guess ngk #R5674-8 or ac mr43t.i thought ac plugs were to hard to read because there dark almost black color.THANKS FOR THE REPLYS,SEAN