340 Sparkplugs

Nevermind what the plug came in or what it was made for. The bottom line is how it acts in your engine and car. Considering the inexpensive price of plugs, this is something you can afford to do a trail and error test.

Personally, I can't stand Autolites in my MoPars.
I've run a lot of different manufacturers plugs and personaly like the Champs best. But that's me and my engine!

It is IMO that you start with the stock 340 plug and then try a step cooler. Then 2 steps cooler. See what the engine like the best. Dodge Freak makes a good note. HIS engine like one thing, MY engine like another.

At there cost, enjoy the experimenting. Go enjoy some track time for back to back testing (be aware that conditions change through out the day and will effect the slips more than the plugs will) or long distance traveling for mileage and drivers feel.