spark plugs for 318

I use Champions.

Just don't use those E3 "diamond fire" plugs they come in a green box. They are total crap. I ran a set in my 360 for 2 weeks and at first they kicked *** but a few days later my tach was bounceing at idle and it felt like I had 2 dead cylinders. I swapped a set of used Champions I had on the shelf and it ran fine. I took them back to the store and they gave me back my money (all 50 bucks) after I told them what happened. The kid at the counter got all excited and said that he put a set in his slant six duster and was having the same issues and was trying to figure out what the problem was.