Emergency-DIY's help--intake manifold fitting

How's my fellow Silverado folks doing. I'm a Denali owner, but see you have many more hits here so thought I'd bring a problem here as I need quick help. Here is the copy and paste of my thread in the Denali section. Hope one of you may be able to help me. I'll check back real soon.
Okay here's the porblem. There is a fitting on the 350's that goes from the heater hose to tight side of the intake manifold. There are two versions one has the fitting in the front of the manifold, the other directly in the middle on the right (sitting in vehicle) side. Mine is the one in the middle. That's probably pretty irrevelant. Anyway's, they are a easy fix.....usually that is. I quick disconnected the hose from the fitting with the plastic clip. Proceded to take a I beleive it was a 1 1/8 open end wrench to the fitting when I begin to turn the fitting it snapped leaving the threads in the intake. ... ****,****,mother ******, whatever you want to say. So, I head down to the local radiator shop. Evidently this happens to about 75% of the vehicles. Being the knuckle head I tend to be, and refusing to pay $100 to get it down by them , I decided to take on the task myself. So I go out and buy a hacksaw that will fit and some dental picks. (no easy outs or reverse thread tools this size available.) I cut the majority out after peeling away the old threads, I find I did a good job as all the intake threads are still there, however there are two rows of threads with the old threads stuck inside. Can't saw at them as I will cut the threads around them. So I try to dental pick them out of the threads to no luck . I've tried and tried with the dental pick. Even though the material is soft enough to snap 75% of the time. I'm still stuck not able to get these out. They feel as if they are weilded in, maybe the heat got to them I dont know. Anyway's I'm wondering if anyone has had to deal with this before? My other car is a probe, I really can't put the kid in that car. Any help anyone has would be greatly appreciated. In the mean time I'm going to check prices on a new Intake and gaskets. ANYONE WHO HAS ANY IDEAS WOULD BE AWESOME.

Okay here is what we did to my father in laws astro (4.3L v-6 same problem as yours).

We bought a galvanized pipe nipple, i think it was 1/2 in or 3/4. anyway we took a cutting disc and cut slits in the threads of it, so that it would work like a tap and then screwed it in and out several times, eventually working the threads out.

Auto parts store has a special rethread tool for about 15. It is a standard 1/2 inch npt pipe thread. Home Depot, Lowes. Get a replacement nipple for an older truck,about 5 bucks, 5 feet of hose, 2 clamps.

Okay here is what we did to my father in laws astro (4.3L v-6 same problem as yours).

We bought a galvanized pipe nipple, i think it was 1/2 in or 3/4. anyway we took a cutting disc and cut slits in the threads of it, so that it would work like a tap and then screwed it in and out several times, eventually working the threads out.

This is exactly what I did, and it works! pay attention to the working it in and out several times. Each pass you dig in alittle deeper.

Thanks for the help fellas I posted this in 3 areas. The yukon section got no replies, the other some guy told me to easy out it (Like I anything left in the center to easy out), and the most value came from you guys. Even though I'm a Yukon owner; I think I'll be posting with you guys from here on out. Thanks again. Keep up the excellent work!!! :lol:

Yep, that's what you have to do. I used a hacksaw blade and ground down the back side until it would fit down inside the broken nipple. Worked it by hand until I could fill the blade teeth start touching off on the manifold threads. The nipple is very soft. Made about 3 cuts inside the nipple and very carefully broke the old pieces out. Like the others said, you have to finish it off with a pipe tap. Don't just screw it in like a new nipple, make a 1/2 turn, back it out, repeat. Told a couple of buddies about this and they changed theirs out at 30 k, nipple didn't break.

It's a shame you have to go to a parts store and get a better part than the dealer. I put the zince plated steel nipple in, about $12. Funny, when I walked in, I showed the parts guy and he just turned around and picked up a new one. Didn't even have to tell him what it went to. The factory nipples are made of something soft like pewter. That would be really bad if you were on a trip and this nipple broke, wouldn't have taken much side pressure o snap it off. Whatever engineer decided to use this type of metal nipple and whoever agreed to it.....needs to have their asses throughly kicked from one end of the shop to the other.