Hi all, I have a 2002 Z06 383 stroker track car that has mahle pistons, OEM ignition, crane cam, ported heads and headers on pump gas 93. I have no idea what compression ratio or size of cam unfortunately. Currently it has NGK TR5IX Iridium spark plugs, my question is is this a good plug? It runs at full throttle and no street use, but I have read a colder plug might be in order? I also heard silver tipped plugs might be a good choice? THX Brian