Which plugs are best for performance?

Champs are the OE plug. I find them (& AC's) to be the best plug for my MoPar's. I do not like the Autolights. It seems to me the engine runs flat with them. Some guys love'em. I say use what works best for you, or your engine really.

The cost of the plug is inexpensive because the materials are not exotic or hard to find/make. Plug cost is the last factor you look at. You should ignore cost when it comes to ether performance and/or long life. Getting both in older cars doesn't really happen. And it's not the plugs fault!

Your local AP store will have the number.