Ok ive been doing a full tune-up and it was time for plugs. Only having a few after market mods, I wasnt sure to go with 1 range colder or stock heat range, so eventually I went with the ngk tr6ix which are iridium. They come gapped at .035 and i opened them to .043 cuz ngk website says not to gap them more then +/- .008. Now i have a weird putt puff noise at idol coming from exhaust and more vibrations than usually from motor. I think its misfiring or plugs causing to run rich or lean. Thinking about going to some motorcraft or autolite copper plugs running stock heat range... What you guys think? Any comments appreciated.

 

I think im going to try either ngk tr55's (copper plug with stock gap and heat range), motorcraft's someone recommened, #AGSF32C and #AGSF22C (they are copper but what are they gapped at and where can I find them?), or autolite 103's or 104's. hehe Ive managed to confuse myself...

 

If you wern't having any problems before the change I would go with the same manufacturer and gap as was in it before. Does the misfire get more pronounced after the engine has warmed up or is it pretty much the same no matter what the temp?

 

You dont need to run colder plugs on your motor. I would either use the NGK TR55 like you said for the stock heat rang autolite ones cause there soo cheap.

 

i got the motorcraft AGSF 22Cs and I think Randy said to gap them at around .48-.52.

 

Ok. Weird thing happened. I ran my car for a couple of days and the misfiring/put put noise from exhaust seemed to have gone away and car is running good. Maybe the computer just needed time to adjust to the new plugs. Strange.. Thanks all though. Next set of plugs going to be copper cuz ive read better things about their performance.