Different plugs will not net you any significant gains.
Go with the OEM plugs.
Snake oil salesmen (We have a couple here) will of course tell you different, but can't back up their claims with anything but anecdotal "evidence" or "tests" they themselves did to arrive at the outcome of their choosing.
James 1:25 Ordered from Faulkner Chevy #NKCF02 1100 5/8/9 2000, 3300 7/16/9 TPW 7/20,GOT MY (low) VIN! 4000 7/24/9 ,Picked up 8/7/9!!! Signed Litho #45. Car signed by FBodfather 2011. Service: Jennings Chevy in PA. We don't "drift", kiddies... we POWER SLIDE!
MOTM/COTM Sept 2012 Pro Patria Vigilans
Click the pic.. I don't tolerate fools.