I do not rate Champions (Others will disagree...) I had loads fail in road going motors - both electrical and mechanical - I switched to NGK's and have never had a failure....
I used BP7ES on iron headed 440 at around 10.2:1 with big cam...race only, found these worked slightly better over 6's with a lot of fuel going in on my set up, never had a problem whether on mtr or on 175hp squirt.
Used 6's on the 340ci with 250hp squirt..not a sign of a tipped plug ..perfect.
If your running an MSD 6 or 7, don't go massive on plug gaps as some will suggest, keep it down to around .30 thou.
I think its was mostly just advertising splurge Steve, remember pictures of a big massive spark on the ad.....theory being that a big longer duration spark will ignite your mixture better, not technically incorrect...but not quite reality as we know in all applications
plug heat range is very important when gapping, i was running too colder plugs and closed the gap fairly tight but now i think the heat range is about right but i still run around .035 with msd.
I use the v power non- projected NGK's, although, i prefer the Autolite equivalent but they are more expensive.
Mick
An NGK plug has a broader more flexible heat range spread in any one given plug number over most other makes, thats why they work so well straight away and give no problems.