Spark Plugs

[Forcefed02]

I'm getting ready to change the plugs on my GTP and have read that iridium & platinum plugs should not be used because they tend to run too hot in our engines. Has anyone else heard of this? If this is true, then I will go with the standard NGK v-power plugs. Is the TR4 plug the correct one to go with while using the stock SC pulley?

[Ripn12s]

I'd try Autolites

Autolite 605 is the plug you'll need
Autolite 104 is a few heat ranges colder

$1 a plug, I've been running Autolites for over 2yrs and couldnt be happier

[Forcefed02]

Thanks. I did some research and checked what plugs came in the car from the factory. They are the NGK brand premium double-tipped platinum plugs. I also found out through the NGK.com (411 site) that iridium plugs are safe to use in our supercharged engines. Supposedly, the iridium plugs require less voltage to produce an equivalent spark than the platinum (or standard) plugs would. This translates into better fuel economy (which we can all use) and possibly a slight increase in power over a standard plug.

[kilroypr]

I am using the Delcos(2 heat ranges cooler) because I am using a smaller pulley. If you have no mods then you are more than ok with what you got.

[kustomkid54]

What's the number on the Delcos? Thanks