greetings haha....truck started having a bit of a misfire tonight, pulled and checked and spark plug was worn fairly down...I heard around here the autolite 3923 is kinda a little known gem for these engines being 1 step colder than factory specs, is this true? Mine has 224k miles on it with unknown history if that matters, got it about 5 months ago and it drove perfect till tonight. I plan on either just getting the 3924's from oreilly tomorrow or waiting a day and getting the 3923 on amazon. Going to be getting new wires and brass dist. cap and rotor for good measure too, those have got to be pretty old and worn if these plugs are that worn down and old looking. Would never have guessed it with how good it drove around before, I may be quite shocked how the truck drives and starts with a fresh tuneup :P

some people claimed the 3923 made a huge difference, some guys said it didn't help any at all.....it seems like it wouldn't hurt to try though, I believe I read it can reduce ping?

edit: crap amazon only had 2 3923's, I'll just get the 3924, I'd appreciate first hand experience anybody has with the 3923's for the future though, I'll eventually need some more again :P

from all the reading I've ever done, platinum are considered taboo for the magnum engines, do they really run worse with them? They'd last alot longer than normal copper plugs

 

Go with the one colder from stock, It will help with ping unless you fill up with premium. Stay away from anything but plain copper autolites. Had them on mine since i got it after trying other plugs.

 

That certainly was not quick....

 

No on autolites. I fell for the hype and my truck hated them. Also stick with stock heat range or mileage, carbon, etc. may get worse. There's a reason they're sold at wally world.

I use OEM Champion plugs without the extended nose (RC12YC) and I'm also at 224k and running great.
Copper plugs, brass cap and rotor only.

 

I used autolites on mine before and they were garbage. I switched to e3 plugs, 8.2mm taylor wires, and a performance distributors brand distributor. This combo made a huge difference.

 

My truck didn't like Autolites either, mine runs best on NGK Vpower copper

 

+1 on this...

 

autozone was out of the 3924's so I got some acdelco coppers, got the first 3 on the driver's side in, have spent the past several hours trying to get the back driver one out, the old owner must have not changed these old ones out in forever they look pretty worn out and dirty and rusty.... I think the spark plug socket on the spark plug itself has become stripped, when I go to turn the ratchet it just keeps turning really easy yet the plug itself is still pretty tight in the engine.... going to rest a bit then walk to the store for some PB Blaster and let it soak and try again, not sure what else to do. That back driver one was so old and brittle the white porcelin part broke off which took awhile with me getting a coat hanger to scrape the pieces out, didn't want that falling down in the hole...

the joys of getting a vehicle the previous people neglected....

I was able to wiggle off that last driver's little spark plug dust cover cylinder thingy if that helps any

 

Yeah, taking the heat shields out makes life easier. You don't really need them in any event.

Chemicals are your friend. Clean out around the plug as much as you can, then drown it with chems. Let it sit for 5-10 minutes, then try and pull it out. May have to tap the socket down onto the plug, to make sure it is actually ON the plug.

 

Be thankful you don't have a Ford 5.4 3valve!!!!! If you don't know, they have quite the rep for spark plug issues. Type it into youtube sometime when you're bored.

I learned a long time ago to only start a project at the hardest side or the part that is most difficult to remove, e.g. plugs seven and eight. Then if I'm stuck on it, I haven't a job half done. But you'll get it. Thank God for cast iron heads!