So I've got about 13K miles on the replaced plugs motorcraft plugs. I accidentally/inadvertently put in the wrong plugs because the Oreilly's guy sold me the wrong plugs...SP462. Those are for the 4.6L engine. My bad for trusting an auto store teenager with an inaccurate computer. I couldn't find any posts that specified if there was actually any difference between the SP462 and SP507 plugs and the truck ran just fine. But I didn't want to take any chances. I was able to get 8 new SP507 plugs on special at Advance Auto for $40, so I figured what the heck.

They all came out just fine with about 35 ft/lbs of pressure. All the anti-seize had burnt off and you could tell where the carbon was starting to build up around the metal sleeve. But, for the most part they looked fine. The SP426 is a little bit shorter than the SP507 and end of the plug and strap is a little different as well.

 

thats pretty interesting. Do you have any pics of the plugs after 13k and after removal?

 

I was surpised at the amount of rust and crud. The anti-seize that remained was reduced to a gritty, dirty powder.

 

Here's what mine looked like after 35K, second set of plugs.

 

So, i take it that when you put the anti sieze on it, they come out a whole lot easier. I'm getting ready to tackle it, i just turned 50k(first set). I'm debating on motorcraft or champion. But if the second set doesnt break then i'll probally go with motorcraft.

 

In my case, the answer is yes. Plug change number 2 for me took less then an hour including the min 15 minutes soak time per the TSB. But I have read about folks who broke plugs on round 2, so follow the TSB.

Good luck