Sorry if this topic has been beaten to death in the past, but after reading through some of the message threads I am still somewhat confused as to what plugs I should use in my stock 2000 GTP.

On the one hand, I have previously used Bosch Platinum +4 plugs in my '97 GTP with excellent results. However, I double-checked the Bosch website and it lists the part number for the GTP as 4459, but also notes "Excluding Turbo and Supercharged Motors". To me, this indicates I should NOT use this plug, correct?

On the other hand, one of the threads I just finished reading indicated that the most current OEM plug for this car is part # 41-101, which may in fact be the NGK TR55IX plugs rebranded. I happen to have a set of these NGK plugs available, but had been holding off installing them util later this year when I plan on doing some mods since I thought they were not recommended for a stock engine. If the new OEM plug is an Iridium plug similar to the NGK TR55IX, then would I be better off just using them now?

Anything that can help clear this up for me would be greatly appreciated. AutoZone part numbers would be an even bigger help!

Thanks,

Eric

in my opinion, for your car you would probably be better off just putting the stock plugs in it. i have no idea what the part number or what model plug i got since it has been awhile. all i know was that i went to the dealer and told him what i had and needed and got somemore. i know they were ngk's though!

Yes stay away from the Bosch +4s. They'll create so much KR you'll hate it. And stick with stock plugs for now until you start modding.

Agreed. If it's stock, don't worry about plugs. Now, if or when you mod, then the fun begins.

I actually used the +4's in my '97 GTP a few years back, and actually REDUCED KR over the stock plugs I removed. Strange.

If the stock plugs (41-101) are now iridium plugs, are they much different than the NGK TR55IX?

Correct. The AC Delco stock plugs (41-101) are now iridium plugs. When I ordered mine, they were labeled as iridium instead of platinum. I can also tell by the needle .

Recommend sticking to stock. When mods come, go to a colder plug.

In this case, the stock is A LOT better than the aftermarket.

Bypass the spitfires. Never heard anything good about them. Plus the theory of two electrodes or evern 4 is bad. The arc won't split. It will just go to the node that has the least path of resistance.

Your KR probably reduced because the older plugs weren't that good anymore, unless you experimented wth new regulars and new +4s.

The aviation industry requires dual posted plugs only because if one tip fouls out the plug will keep firing.

what about the AC Delco rapid fire plugs? are those OK?

Stick with OEMs if your not gonna mod. GM's igition systems have always been top notch and hard to improve on.

If still tempted to try out other plugs, think about it this way.
If you go with the OEM, you can use the extra money for other mods.