Here are my sparkplugs. I just replaced with Autolite XP Extreme Performance Iridium. Any input from you guys/gals on the state of the old or the choice of the new?

The old plugs don't seem to point to a specific engine problem. In fact the old 1992 460 runs very well. I really can't say it runs "so much better" now that it's got the new plugs....I took it for a quick spin down the freeway and punched it a bit....don't really do that with it normally, so I can't compare. Now that I'm staring at the state of the old ones I'm embarrassed to say I'd put this job off, I let the skin on my knuckles talk me out of it before.

 

The old ones look like butthole and very old. I would have went with copper Motorcrafts.

 

Other than being pretty worn, there is not anything unusual about the appearance of the old ones. Iridium plugs are pretty expensive and maybe overkill for a truck, but if it sparks reliably, you'll be just fine. They might last a bit longer than the standard plug, which could help with the knuckles .

 

The Iridium have a $2.00 each rebate through Nov 2011, so they were only about $3.00 each.

A record 2 scraped knuckles....love American trucks. Used anti-sieze on the threads to make it easier next time.

 

Looks like the bottom ones have an oil problem, probably a valve seal. You might also have some carbon buildup in the cylinders, try some seafoam and see if it helps.

 

I'll second the comment about Motorcraft coppers.