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The manufacturers say NO.
This is because most people do not know how to properly gap a spark plug, and the center electrodes on the ultra-fine iridium can easily snap if mishandled. There is no warranty for snapped center electrodes. The manufacturers say an iridium spark plug will run so much better than a traditional plug, even if it is not gapped for that motor, that they would prefer you just leave it rather than risk snapping the center electrode.
hope that helps...
UDRIVESLOW
if you are in so cal and want perf. mods with gm warranty email me.. UDRIVESLOW@YAHOO.COM
I emailed NGK just last week asking them about the TR55ix plugs for my car. They said the same thing, that regapping is not recommended because most people use the wire type plug gauge and they damage the thin electrode. The TR55ix comes out of the box at .059 gap and NGK told me that even though the 98 Corvette's recommended gap is .050, the iridium plug would work just fine at the higher gap. What is the specified gap for the LS2?
are the tr55ix and tr5ix the same heat range as stock or cooler? are both of these iridium plugs? thanks
The TR5 and TR55 plugs are the same heat range as stock for the LS1, so if the LS2 uses the same heat range as well, then yes it's the same.
Anything with the ix at the end of the number is the iridium plug, so both the TR5ix and TR55ix are iridium. One thing to keep in mind is that they are only iridium on the bottom, so they don't have the same long life as the OEM iridium plugs, which use iridium on both sides. So the NGK iridiums are not rated for 100,000 miles. (from talking with the NGK tech rep they said they are good for about 50k, depending on the condition of the engine and driving habits of course)
The TR5 and TR55 plugs are the same heat range as stock for the LS1, so if the LS2 uses the same heat range as well, then yes it's the same.
Anything with the ix at the end of the number is the iridium plug, so both the TR5ix and TR55ix are iridium. One thing to keep in mind is that they are only iridium on the bottom, so they don't have the same long life as the OEM iridium plugs, which use iridium on both sides. So the NGK iridiums are not rated for 100,000 miles. (from talking with the NGK tech rep they said they are good for about 50k, depending on the condition of the engine and driving habits of course)
thanks, i could be wrong here, i remembering go to ac delco website and it only says the center electrode is iridium, it doesn't say anything for the ground electrode