They're spark plugs....

I'd put stockers back in

 

what about the TR6 ngk plugs? I was told that the TR6 plug will give the best forgiveness when playing with timing. In other words when advancing timing due to the plug running colder it will have a less likely chance to ping out. I am running the TR6 in my 06 not sure if the are any better or worse than what I had.

 

those are for no2 or boost for the most part.

 

do you see a problem running them on a bolt on n/a 5.3?

 

Better for what, wearing out quickly? Don't get me wrong, I'm running NGK TR55 coppers in mine, but they are a 15-20K plug and that's it. Iridium plugs can easily go 100k on a well tuned engine, and supposedly allow for a cleaner burn with less carbon residue as a result.

I've said this before...if you wrench on your truck alot, and don't mind replacing your plugs too often, go with the NGK TR55's. If you want something you can stick in there and leave alone for a long time, get either Delco or NGK Iridiums. Platinum is a middle of the road plug in between both, it lasts longer than copper but not as long as iridium.

A couple of notes...iridium plugs come pre-gapped, do not attempt to gap them in the conventional manner or you will snap the micro welded iridium tip off and may not even know it. Also, install some anti-sieze on the threads of the plugs so they'll come back out if and when you need to remove/replace them again.

 

Copper plugs are crap...they dont last for **** due to copper being soft metal....platinum are better than copper but the best are the Iridium, which is the hardest metal for plugs...so OEM AC Delco 41-985 for N/A

 

Yea, I've got a set of NGK Iridiums that will go in when I do my LQ9, just using the TR55's I have now as I was experimenting with them. FWIW, I tried a few different spark plugs in my truck to see if there would be any difference in idle quality or whatever, and they all performed the same. I had originally had factory platinums, then Denso Iridiums, and now on my second set of NGK TR55's. Something interesting, when I removed my factory platinums at less than 40k, the gaps were inconsistent across the board, ranging from .040 to .065.

And I do believe that the NGK's and Delco's are the same, I've heard of guys removing their factory plugs to find Delco's down one bank and NGK's on the other....I thought I read that someone mentioned their plugs were stamped both NGK and Delco on the porcelain IIRC.

 

I have also heard that about stock plugs being stamped from NGK and Delco both, makes one wonder

 

I got the Delco Iridium 41-985

I'll probably install them this weekend with a new set of MSD wires
I figure these will last another 100k miles no problem, sure you can buy cheaper plugs - but you'll just be checking them more often... and who likes to do taht?!?!

 

i just changed out the plugs in my tahoe. had the original plugs in it and was stil running strong at 89k. i put tr55 non iridium plugs back in it and noticed a slight difference. however if you don't put an iridium plug back in it wont last as long. im putting an ls1 in my tahoe pretty soon so i wasn't worried about longevity.