I'll tell you a tip about spark plug porcelain - you DON'T need to break it out
 

I've been working on a write up with pictures but I haven't had time to finish it. So to help out those that need help quickly this is what I did.

If your porcelain breaks flush with the tip, all you need to do is push it down into the tip with a punch. This is easier on the front plugs but tricky on the back ones. What you do is push the porcelain down and it stretches the grounding strap and it leaves about 1/4" of exposed tip at the top. DO NOT try to use a normal tap as it will NOT work. You MUST use a BOTTOMING tap to thread the exposed top. When you push the porcelain down it will chip a little so you will need to vacuum it out. When the tip is pushed down to the grounding strap it blocks the hole and doesn't allow shavings to enter the combustion chamber.

The back plugs are not so straight forward but I know how to get those out too with a similar method. It involves modifying a cariage bolt and an air impact hammer and CAREFULLY pushing the porcelain down.

Now I just need to get my truck running right from disconnecting the PCM and I will finish the write up that I started.
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Nice post! Its a little dangerous and im not sure i would do it!

week late for me. . .

I think you posted in another thread that you pushed the porcelain down until it broke the ground strap, seems to me pushing the porcelain past broken edges of the strap would likely put some little bits of porcelain into the cylinder...

Nope wasn't me. I pushed it down only until it stretched the strap as I mentioned. You have to be VERY careful. I got two out using this method. Although I was VERY nervous but desperate. The worse thing that could happen is you do as you say and push it too far. Then yes, I would pull the head. But I thought I was at that point anyway so i had nothing to lose. I would do it again without hesitation.

It works