TBK'SS

iTrader: (1)

I bought a set of these plugs and the gap is at 40 out of the box. Do I need to gap them larger? I have been told not to gap Iridiums. Is this true?

TBK'SS

iTrader: (1)

Anybody have suggestions? I tried a search but found nothing directly related.

senicalj4579

iTrader: (41)

my gm manual says gap should be 0.06in.

TLUZLS1

iTrader: (6)

Dont gap them, from what i can remember they come pre-gapped.

SSpdDmon

iTrader: (10)

No, leave them alone. They changed the gap specification a few years back. I'd look for the post, but I'm going to ask you to take my word for it. If you were using regular NGK TR-55's, then I'd say .055.

*Edit* For the skeptics:
https://ls1tech.com/forums/generation-iii-external-engine/442984-gm-iridium-plug-replaced-orginal-platinums.html

TBK'SS

iTrader: (1)

Thanks for the input. I put them in without changing the gap and my car seems to run fine.

bczee

iTrader: (12)

The manufactor of Iridiums and Platinum plugs don't recommend regapping these type of plug due to the fact that the Iridiums or Platinum on the tip might crack and cause failures.

senicalj4579

iTrader: (41)

yeah thats right i forgot about that. when i did a plug change a couple years ago i gapped mine at .040. i also remember some of us thought the reason they were saying to gap them at .040 from now on is because over a little time the gap gets bigger and ends up to be around .060 - .070 or something. who knows lol