I think Champions are good I fly behind them and so far no problems and use them in most of my toys and at work. I don't even have problems with the plug that comes with the engine kit. I do modify them and the post is on this forum and I run less gap .020 to .017 or what ever will make it run the best I cheat, plug gap is only a recommended thing ,and I don't play by the rules all the time.
Norman