I’ve got NGKs in my 11B for at least 10 years now and haven’t had a problem with them but I understand that they can come up defective. I’ve used Bosch plugs with good results so I may try those next. I bought a set of NGKs so I will try them and see what occurs and if all is well, I will stay with them. With Champions I understand that the connector on the plug does not unscrew so I can’t use NGK motorcycle-type connectors which I think are the best around. They’ve been on my 11B since the 1980s and I have them on the 49BL. I’ll get back to the car this weekend as right now I’m in Northern Ontario on business.
Larry Lewis