[Tim Corcoran]

If you drill the hole your going to put the chips inside the engine. Do you really want to do that? Do you want to tear down the engine to clean it out? You don't need the hole, I have raced my Pontiac for many years never had a hole there. Forget about it and just leave the plug along.

[Dragncar]

Heat is your friend here. A few heating and cooling cycles is going to shrink that plug and it might come out easier than you think. Those short-tappererd extractors in my link are not going to break. You just need something to grab what is left of the jacked up 5/16" square hole and get it moving.
Just remember, do not quench it. Good steels get very hard when you heat and quench them and after then you are not drilling it out. Grade 8 bolts get basically made into steel as hard as a center punch when you heat and quench.
Not sure what the steel is on the factory square head plugs but I would not take the chance. I have taken them out after I drilled a pretty big hole in them. Then heat and quenched and it backed out with a easy out.

[RocktimusPryme]

Originally Posted by Dragncar

Those short-tappererd extractors in my link are not going to break. You just need something to grab what is left of the jacked up 5/16" square hole and get it moving.

I never had any luck with those, but I always thought maybe I was using them wrong. I developed a lot of coping mechanisms to get rusty hardware out WITHOUT using any type of extractor because once I got to that point it was almost always a battle.

I always liked the look of those short ones over a traditional long fluted extractor, which I hated using, but I could never get those short guys to work. I think maybe its because the hardware I used was always on the small side, a lot of #8 Allen Head stuff. Just didnt provide a deep enough engagement on the small hardware.

I cant find the exact kit I ordered for work because it was on my work email but this kit has a bunch of the same stuff. Once I found these, they worked killer for anything where your tool went into the fastener (like an allen head rather than a hex head holt) I dont think they ever failed me.

https://www.mactools.com/products/smxve51rbrt

[Bill Hanlon]

What Shiney is talking about is one like this Klein Tools piece.
https://www.homedepot.com/p/Klein-To...E&gclsrc=aw.ds

My brother used one on his Ducati 250 a lot back in the late 60s.

[mgarblik]

After reading this thread, I am a little unclear if the engine is ready for a rebuild, already back together? Guess I am unclear about the concern of chips in the engine. If you don't want metal chips in a finished engine, you can't drill out the plug. Drilling WILL be required to remove it. So if the engine isn't coming apart and you just wanted the little .030" oil hole for the distributor, I would just forget it and leave it alone. Millions of Pontiac engines ran their entire life without that hole and without gear damage.
If the engine is coming apart, stand it on end and drill through the plug with a 3/8" drill bit. Then take an oxy acetylene torch and heat the plug and the area around it cherry red. Turn torch off and let it cool 3-5 minutes. Take a candle or a piece of paraffin wax and touch it to the plug. If the wax smokes to vapor, it's too hot. Wait a couple minutes. Try again, you want the wax to melt with minor smoke. Once waxed, wait another 5-10 minutes. Now tap the KD extractor into the hole. Use a socket and extension and ratchet or an adjustable wrench and the plug will come right out very easily. We remove hundreds of stuck plugs just like this in every kind of engine you can imagine. About 1 out of 50 may require re-heating. In over 20 years of removing plugs this way, we have had 1 extractor break in a plug and it was a tiny 1 in a 1/8" plug. Never heat the plug with the extractor in place. Remove it first and let it cool some before putting it in. Heating the extractor will damage the heat treat. Simple process. The extractor kit is KD 720. Inexpensive and it has sharp cutters on it. Spiral extractors, no matter what brand are crap compared to these. Very hard to break one, but nothing is impossible I guess.

[Dragncar]

Originally Posted by RocktimusPryme

I never had any luck with those, but I always thought maybe I was using them wrong. I developed a lot of coping mechanisms to get rusty hardware out WITHOUT using any type of extractor because once I got to that point it was almost always a battle.

I always liked the look of those short ones over a traditional long fluted extractor, which I hated using, but I could never get those short guys to work. I think maybe its because the hardware I used was always on the small side, a lot of #8 Allen Head stuff. Just didnt provide a deep enough engagement on the small hardware.

I cant find the exact kit I ordered for work because it was on my work email but this kit has a bunch of the same stuff. Once I found these, they worked killer for anything where your tool went into the fastener (like an allen head rather than a hex head holt) I dont think they ever failed me.

https://www.mactools.com/products/smxve51rbrt

I have removed lots and lots of broken bolts, countless. And these extractors are not my go to option. But.... he has some issues going on. The stripped plug is in a hole and he needs to try and get it out without drilling a hole. You need something to grab the old square hole with, these will get you at least some traction.
I have removed lots of broken bolts with a torch and a screw driver. Take your torch and you start hollowing out the middle of it without going through, hit with water. Keep doing that and you get a little inverted cone, hit with water. By then the bolt shrinks so much it is loose and moves with just a flat bladed screwdriver you just jam in the hole and turn.
He can do the same thing. just do not hit it with water and these will grab enough to get it turning.
You need something short with a lot of tapper, these are it. if you are going to drill a hole all the way though you might as well use a standard easy out.

[sdbob]

When I was in my teens I took a 3/8 extension and ground the end to fit those plugs. When I use it I rounded the plugs out. Then someone told me to get a plug removal socket from snap on for those plugs. It had worked every time. I tried to put my tool beside snap ons to see what I did wrong. I made my tool to sharp on corners. I believe you want the flanks to drive. I've used that snap on tool with my impact driver I hit with a hammer spinning plug out.