I would use NGK copper, the one that cost $1.99, it made best performing, just dont last long, around 30k miles. I use it on my mustang gt and both camaro z28 ( yes I own 2 ). A month ago I bought a camaro z28, and the owner put in denso Iridiums, I take it off and put in ngk tr55 copper, call pull to red line with no more miss like the iridiums.