The reason that I asked is I have done tune ups in the last few years with Champions and had issues. I know they were 1st choice decades ago but have they changed?? It seems like Autolites work well in everything I use them in.
Pump gas and under 11:1 you'll need the RC12YC champion.
There is a reason the Champions don't last as long. It makes sense if you know why that is. Expecting a set of plugs in a performance engine to go more than 10k is silly. Plugs are cheap. Replace them every 5k and the tune up is better.
