Does it work? Just curious, because of just blowing a plug, they looked like they would grab the threads that were still there. I just wanted to know if they seated the same as the triton plug, but ran in deeper. After reaming out all the cylinders on my 5.4, I noticed there is probably enough room to put the ztech plugs which would grab a lot more threads. I do know this would change where the spark is in the cylinder, but I think it would fit. There may be other factors, like it would increase the compression due to taking room out of the cylinder, therefor increase the chance of launching your plugs. Anyway, I was just curious if anyone has tried this maybe with the head out.

 

I should probably add that I am not currently considering this as a repair, I already put Big-Serts in 5 cylinders, just waiting for the rest of the inserts to come. Just curious, because I was considering it originally.

 

You need to be careful if you put plugs in that have a longer reach because you don't want the piston to slam the bottom of the plug on the upstroke. Major damage.
Also you can have a plug that has three inches of threads and the head with 1/4" of threads. You will still be holding on to only 1/4" of threads no matter how many threads the plug has.
Make your plug choices wisely. I would suggest using what the factory says to use, Motorcraft plugs with the same part number that was originally equipped in your truck.
Good luck.

 

Hmm, it sure looks like my heads have at lease 2 - 2½" of threads, even though the factory plugs only use 4 threads, there are many more. The reaming and threading tools I used were all 3" and ran all the way down, yes the piston was down for each one . Anyway, like I said, I am only curious, I'm not searching for the best price to buy them, just bought new Denso's on Saturday, I won't be buying any anytime soon, I hope...