I have had no problem with either the Champions or the NGKs. I do a little work to my plugs, though. I cut the side electrode so that it only extends a little way over the center electrode. I then gap them to 0.040". That's worked great for me.
I tried Magnecor 8.5mm wires for a while, but the set I had were a really tight fit on the plugs, even using boot grease. I had a hard time getting them seated properly. I'm back to stock wires now.
I tried Magnecor 8.5mm wires for a while, but the set I had were a really tight fit on the plugs, even using boot grease. I had a hard time getting them seated properly. I'm back to stock wires now.