So I decided to change the plugs in my 02 Durango 4.7 (what happened to good old spark plug wires?). Anyway, I wanted to use standard copper Champions. The auto parts store gave me RC12MC4 plugs and said those were the ones I needed. The plugs I pulled out of the engine (which definitely needed replacing) were RC12MCC4 plugs. Is there a difference? It looks like the new plugs projected further than the stock plugs I took out. The truck seemed to start easier and idle smoother but I'm not sure it was actually running any better while driving it, not like I thought it would considering the condition of the plugs I took out. Are the new plugs essentially the same plugs even though they seemed to project further and were missing the one letter?

 

Please fellas not all at once! You can respond one at a time.

 

??? I don't have a clue it is probably fine but you could check with the dealership they would be able to tell you.

 

I put autolites in mine. It runs great. I had to open the gap though...

 

LOL. 5.9L owners are speechless becasue we can't relate. We DO have plug wires, rotors, a distributor, cap, etc.

Autolite's are good for the 5.9s. On your 4.7L, I suggest one range cooler than stock in the NGK plugs.

http://www.ngk.com/

IndyDurango