Changed plugs for first time yesterday. The guy at kragen gave me 2 leading and 2 trailing. When I pulled the old ones out the engine they were all 4 leading. Did the previous owner make a mistake? I replaced them with 2 leading and 2 trailing. I noticed little difference. Is it bad for the engine to have 4 leading plugs?

 

No i dont think that it would have been that bad, the car still runs right? Just put the proper ones in there and go. Yea, he prob just made a mistake, or the parts store did and he just didn't catch it. Parts stores have alot of damn problems, and usually i gotta argue with them to get what the hell i want. I just about gotta go off to get the proper stuff, but they wont take you telling them there computer is wrong.

-Chris

 

Mine also had all of one or the other, I cant recall. But when I bought it the previous owner told me to get them all the same but ive always got 2 trailing and 2 leading.

 

Modified TII's should run bur9eq's all around, or even a coulder plug if really modified.

-Chris

 

i changed to all 9's in my TII. now i'm going back to 7's and 9's for the winter months