Just because a car that was stock came through the assembly line 50+ years ago with a champion plug that the company had a business contract with doesn't mean it's the best today. I have no issue with champion plugs. Get the right heat range, that's the key.
I run NGK's. They are currently used in everything from high performance engines to economy cars that will go 100+ thousand miles on a set of plugs. They work well for me. I can go 1-2 years on a set of plugs. I change them out of habit, not necessity.
