Thanks for the help guys. You never fail to answer my questions. I am running two brand new 9's and the cars loves them.

has anyoen actually melted a 7 cold plug in a properly running engine? under 15 psi ?

the 7's are more prone to detonation, seeing is how they are a hotter heat range.... bottom line. if you have a highly modded fd, 9's are better insurance......

I ran all 10's and yes they do foul out if you don't drive hard.

Three words: spark plug cleaner https://www.nopistons.com/forums/pub...#>/biggrin.png



Just as an FYI, I once gained 18 rwhp on the dyno simply from swapping 10.5s in for 9s. Went from 310 to 328. I will say that swapping out plugs on the dyno *sucks*! I burned the hell out of my forearm. It was so long ago I really can't remember my mods.

So if i get iridiums, should i get 9s as well????

By Iridium are you talking about the HKS plugs? Be careful---if I remember correctly, Ernie T lost a motor when the damn electrode came off the plug on the dyno and (obviously) lunched his motor. Vosko, can you validate this? My memory ain't what it used to be--damn Jager https://www.nopistons.com/forums/pub...#>/biggrin.png

Damn Rich.. you have all the bad stories... between your bad gas story and now this. I dont know what to put in my car... lol



BTW.. where did you get 10.5's at???





Bret