Best plug I have used so far is Denso iridium plugs,always have liked NGK or Denso plugs in every engine.
Gus

You have got to be joking ! Someone who thinks Bosch are OK? Those are the worst plugs I have ever seen! By far! I am a full time mechanic and have been for the last 15 years and have seen sooooooooo many people do there own tune-up and bring us the car a week later and want to know why it runs worse than it did with 100,000 mile (any brand)old plugs, %99 of the time it is because they put some Bosch plugs of some sort in it. I only remember that happening one time and it was not a Bosch, it was an autolite. Personally I like NGK or Denso and every engine works fine with them, either a company makes good plugs or they don't, just like oil filter companies make good filters (everything but Fram) or they don't(Fram). I see no middle ground in either product. Really good advertising and crappy products or vise versa, that is the same reason you see so many Fords on the road, good advertising crappy product. We install NGK as a standard practice in my shop and have never had a comeback for them.

I like Champions but I never had a problem with Autolites either.

Some people say run Champions in SB's and Autolite's in BB's.

I run Champions in everything except my SRT-4. I run NGK in the SRT. The Champions do hold up better when using race fuel than the NGK's. I've ran both in the SRT, and could only get about 5k out of the NGK's during race season. The Champion showed no sign of wear with the race fuel. Only reason I run the NGK now is Mopar recommends them with the Stage 3 turbo upgrade.

I beez liking my J11Y Champions

Hot Rod Dave I agrre with you 110%.Bosch are total junk.I cant count how many I replaced at work because they were missing.My buddy put a set that were like 8 bucks each in his old Buick.I replaced them with ACs and it eliminated the miss he had.They were like a month old.Ive probally replaced a few thousand in the last 30 years because they are junk.My kid put a set in a 61 Polara BB we had.Rant them for like 3 months.Wouldnt start and always didnt idle smooth.I put a set of Autolites in and it fired right up and smoothed out.Rocky

I prefer the Champions. I tried Autolites once when there was a thread like this and the consensus seemed to be that Autolites were better but the car did seem to run better with the Champions. I know that as long as the heat range is the same it should not matter, but the Champions just seemed to idle cleaner and had sharper response. Also the Champions dont turn all rust colored like the Autolites and they are easier to read because they are nickel plated or whatever they, instead of black oxide coated like the Autolites.

On another note I will say CHAMPIONS DO NOT SWIM! If you foul them they WILL NOT WORK RIGHT EVER AGAIN! I've fouled Autolites and they will work, just not well. Ive fouled Champions and the engine just flat out refuses to run.

I have been having really good luck with AC plugs lately. I also run a lot of Autolite 86s and I've still got some Champion RJ17YC in the rotation, got'em for $10 for a carton of 50 some years ago at the Winter Swap Meet in Denver. I use an extended tip spark plug whenever I can. My '64Dog uses so much oil that I am changing plugs often. I thought the super hot Champions were going to do the trick but they aren't any better and after a couple of cycles of cleaning have about a 30% failure rate. Bummer. The Autolites and the ACs work and will clean up and work again.
Tip: Put the dirty plugs in the oven at 550 or if you have a self-cleaning oven run them through a cycle, although I haven't tried that higher temp yet. I also found that soaking them in Ospho first aids the cleaning process.

Also, if you're willing to do the work there are usually many vintage new plugs on the 'bay.

R