I know there has been some discussion about Big Block Spark Plug choices.

How about Small Block Spark Plug Choices.

Id like to hear everyones opinions on spark plugs for both Stock Engnes and performance applications.

I have always been the type to run what Ma Mopar put in the cars from the factory. So my choice is Champion RN14YC (405) for the stock 360 in my 72 Fury Wagon. I also used to run them in a 67 B body I had with a mild cam,Eddy intake and Holley 600 Carb.I never tried anything else,this plug choice worked fine for me and thats why I choose them.

Thats my preference. What does everyone else like to run and what results do you get that help you make the choice?

I have autolites (I forget the #) in my daily driver 318 & they are holding up good but that may be due to the mixture being good (think I just got lucky on that )

Don't know about "best", but Autolite 66 has been fine for me. Inexpensive, and no failures in my 90,000 miles in a daily-driver old stock '72 318. 230,000 original miles on the engine, and still have a nice golden brown on the plugs when I last replaced them.

I used to run Autolite 65's in my 360 and 318s.

That was back in the good old days of USA stuff. Can't vouch for them now.

I run Autolite 64's in my warmed over 318.

I have ran 3 different brands in my warmed up 340

Champions

Autolites were not to bad

Bosch Platnums best I have ever ran

Autolite 3924's...champions

champion RN12YC's are what I've run. never had a problem. on my motorcycle, it ran much smoother with champions than it did with bosch platinums.

We ran Autolite in all the older SBs.Ive only seen 1 car in 25 years that ran decent with Bosch plugs.I cant count how many sets of those I had to toss because they were junk.Rocky

The 12 to 14 heat range Champion plugs factory installed on the Chrysler small blocks were chosen to improve the emissions on the 'cold start' portion of the EPA test.

A Champion heat range of 9 to 10 is probably more suitable for performance and wide open throttle.

Do a search for
Magnum Engine Sparkplug FAQ
for a long listing of modern spark plugs

It is worth reading up on 'fine wire tip' spark plugs with irridium alloy for their pluses and minuses.

It is my personal experience that
choosing a gap on the larger side, (0.45 to 0.65)
and indexing the ground electrode strap so that it does not block the growth of the flame toward the center of the exhaust valve
both have small but worthwhile effects for faster burn
.... but I advise against using copper washers for indexing because they allow the plug to come loose.

I've been using NGK ZFR5F ( stock #7558 ) in my 408 mag heads for a year or so. Gap them at .050". They seem to color good and I like the extended cores as I think it improves the flame front. Had a couple of failures with the wire core plugs in the past and won't be using them again.

I have never run anything but Champion. I wouldnt run a set of Bosch plugs if they were free

11 sec I agree.In fact Id pay to get rid of the Bosch.Like I said in 25 years Ive seen one car ryn decent with them.Even their 5 buck each plugs dont run well.I use Champions in all the newer Mopars.Just like the Autolites in the old ones.Ive been wanting to try NGKs in the Alumimun headed 440 though.Rocky

I run Champions in everything and haven't had a problem. All teh Mopar guys in town do. Including the Hemi Dart and Hemi 'Cuda. Have run Champions for Almost 50 years.
I run RN11YC's or N9Y's if I can find them in the Duster and 12's in the warm street. Champions are a product of Federal Mogul

2x on the autolight 65 plugs,been running them for yrs and no probs

back in the day it was the champ RN12YC,had some luck with them,but did swap up to the AL65 plugs

boush platnums are junk,at least all I have run are...

I was surprised to see such loyalty to Champion and Autolite, what with all the improved electrode designs on the market, now. I'd be interested in a dyno comparison, if anybody has one.

I was also surprised at the rejection of Bosch plugs outright, by a couple members.

I would rather avoid Bosch because it's foreign made and owned, but out of desperation, I bought a set of the expensive "Platinum 4X1"s or whatever they're called, in an attempt to improve the abysmal fuel mileage of my work van. The design seemed to be conducive to a more complete burn, I thought. Though I wouldn't call them "junk" or even "bad" in this application, I also saw no improvement in fuel efficiency.

Has anyone tried Splitfires or E3s? I'll probably never buy E3s as long as there's at least one brand NOT manufactured in Red China, but I'm curious what advantage, if any, there is in the design.

Tried Bosch in my 360 and it never ran right. Put autolite 64`s back in and never looked back.

I wouldn't look at plugs to increase my fuel economy. For plugs I'm looking for reliability - ability to resist fouling. I hear good things about NGK, but had a lot of trouble with them fouling on my dirt bike, so I always avoid them.

I run NGK #7's in my 340 and have run NGK's for a few years now. I like them and they seem to hold up well

well platinum plugs don't conduct as good as copper. a copper plug is more efficient. but the platinum doesn't wear like copper, that's why OEM's switched to them--to increase maintainence intervals, not for drivability/performance.

I've seen tests of all the fancy schmancy plugs, none made significantly more power (not worth the added expense at least) than a traditional plug.