i was wondering whats the best performance plugs ngk or spitfires ??? anyone runniong either one ??

 

IIRC the general consensus here is that the "performance" plugs are a waste of money on the magnum engines. The Autolite copper plugs seem to be the prefered choice.

 

The Champion Truck Plugs or Autolite 3923s seem to be the preferred ones here.

However, some like stock Champions, and some weirdos like me have had good luck with NGK Iridiums.

 

ya i just want a good plug to run with my msd and my superchips what part number for the copper ,arnt they alil cooler plug to reduce ping right ???

 

autolite 3923's... 1 step colder than stock and the preferred plug by alot of magnum engine owners...

 

I've had good luck with Champion Truck Plugs and NGK V power plugs. The Autolite 3923 never ran right in my engine after about 500 miles.

The Projector tip on the stock champion plugs is longer on the newer second gens that the older ones (99 was the change I believe???). I think that might be the reason the autolites didn't work as well. They have a shorter snub nose and the newer engines might "prefer" the longer tip.

This is just my personal experience. Your experience may vary.

 

Nope the Champions seem to be the most liked choice as many of us have had problems with the Autolites.

I had a experience like above. They just never seem to run right after a month or so. Not sure how many miles I drove in that month.

I've never tried NGK plugs in the Dodge but I like them for the Honda's which they are OEM and the bikes.

 

The Autolites ran like shiat in my engine. Mileage went down and I was getting a misfire on #5. I switched back to the stock Champion plug and everything smoothed out.

 

The NGK V-Power ZFR5F11
(stock number 2262, resistor inside 4,000 ohms)
are very good plugs, except for a cylinder that is pinging

The short nose design Autolites 3923's are best used in the cylinder that is pinging.

do a search for "Magnum Engines Sparkplug FAQ"
for a run down on nearly all plugs for 5.2/5.9 V8s

 

i like my 3923's. no problems here.