I replaced my plugs again and it seems the center point on the leading plugs do not last worth beans. Put new ones in and the midrange is a BIG improvement. I'd like this all the time...

Should I be running all 9's? Advantages/disadvantages?

(I'm boosting about 8psi)

 

I just run all 9's anyway...just makes for less confusion to buy and put in. been doing it for 4 years...

not sure if that'll help the problem...but its worth a shot