Quote: Yep Champions are junk, thats why they were the OE plug when these cars were new. I think your problem is running a resistor plug in that motor in the first place. Find a non-resistor plug in the heat range you want and try that. I run old NOS J11Y Champions and have never had a problem. But you pick any manufacture you want and find out for yourself which one you like because anytime somebody asks about spark plugs on here you get a different answer. Its about like asking which beer is the best.
the champions that were installed in the 60's/70's are a much better plug than the new champions , never had good luck running that rj12 in anything either .
Probably right John, but I still got 4 sets of the vintage NOS J11Y's left.
But I still have never seen anybody have any real luck running a resistor plug on a beefed up mill running alot squeeze and a hot ignition. Seems like whatever brand they run the stupid resistors burn out of them with quick.
I think your problem is running a resistor plug in that motor in the first place. Find a non-resistor plug in the heat range you want and try that. I run old NOS J11Y Champions and have never had a problem. But you pick any manufacture you want and find out for yourself which one you like because anytime somebody asks about spark plugs on here you get a different answer. Its about like asking which beer is the best. 
