I am running the Bosch 2's right now, they seem ok. the point of running them is the NGK's which had about 20K miles on them were causing pinging real bad under load. they were worn out. I re-gapped them and put them in and it didnt help. though i'd try the 2's since I have the MSD off road box which will eat up plugs faster. I've heard that the splitfires dont do well in the mag motor, and I might try the triple platnum ones if these 2's dont last. I've had the autolites in there as well and it seemed fine to me back then, before the MSD box.

 

I just put E3 spark plugs in mine and i like them a lot definitely a power difference. But it could have been that the previous owner never changed them even with 80,000 miles on them.

 

Newb Bastardi
Stop diggin' up this old crap and post anew!

 

Calm down ,WayneC! Here take this, just don't ask what I baked in it:



[IMG]local://upfiles/68540/57DC153D1AB34BC39CAA1DD43049DAD6.jpg[/IMG]

 

Since someone dug up this thread, I put in Autolite 3923s today in my 318 and it improved performance and low endtorque a good bit. Don't know if its better than other plugs, because I had 3 different types of plugs in my truck before today (2 different types of AC Delco and 1 champion plug) and they were all gapped at about .30 instead of the .40 that I have now. At the very least I can say the Autolites at .40 seem to be a good plug and a great deal.

And I tried bosch +4s before - and those were worthless in my truck.

 

the 3923's are said to be worth approx 5hp over stock, not sure if it does anything for torque though.

 

The Autolite 392x series of sparkplugs give the most gain
in Magnum engines that are either running chips that have advanced the ignition timing too much...or engines that are using gasolines whose octane ratings are too low for the worst cylinder on that V8.

I am not saying the 392x plug is bad
just commenting on how its short nose effects the engine.

There is also a lot of evidence that the back two cylinders (7 & 8)
run both hotter and perhaps leaner than the other six
on 5.2/5.9 Magnum engines.
People who want to experiment should consider trying different plugs back there...with the Autolite 3923 or 3922 as reasonable candidates perhaps with small gaps as well.

 

Actually, posting in old posts is better then starting new ones in my opinion. It makes the search function more effective becasue you have less posts to look through when searching for a specific topic. I also think it results more often in a thread having some closure rather then being left open ended.

 

I.m running champion irridums with all new ignition parts, and my 5.9l runs like a top.

 

I agree. Sometimes people's opinions change and knowledge is gained which is good. And opening an old subject with new ideas is certainly not wrong. It is good to finish an old thread also. I don't know how many times I have done a search and found many useless threads because they were never finished.