Iridium, thats what it calls for, so thats what it gets.
2013 CC 5.3
81 C10 LS1 project
Greetings to all. I am buying a set of NGK TR55's this weekend and am wondering about the Gap setting. The TR55's are set at .060 out of the box(info from NGK website),BUT the OE delco's are set at .040. Do you run them at the .060 or regap them? If you regap them then why not use the TR5's, they are gapped at .040? I am hoping the stock coils will support the .060 gap.
I ran TR55's at .060 before I put the turbo on my truck. No issues.
2006 GTO M6 Brazen Orange
2006 Silverado CCSB Duramax
Thanks for the quick response and info. Have you ever modified them by cutting back the ground electrode so it only covers have the center electrode to "unshroud" the spark? I used to do it on small one cylinder engines(think 8HP Tecumseh on Snowblowers,etc,) to get alittle more torque out of them. It made a noticable difference especially under heavy load(less bog) and also if the high speed jet had been drilled out a smidge, but they didn't last as long as unmodified plugs,not a big deal for$2 and 2 minutes work.
No, I've never messed with them. I just double-check the gap and put them in.
2006 GTO M6 Brazen Orange
2006 Silverado CCSB Duramax