Well...Let's just say I think I've screwed up. Was changing the spark plugs in my sons car. He was helping out with other issues on it. #1 spark plug I have a feeling has crossthreaded itself trying to get it out. I should have stopped when I started having issues with it, but was hoping for the best. So now I'm gonna soak it and see if that'll help get it out. Now if I assuming right, and worse comes to worse, I'll have to take the head off this thing. I got to think and wondering, will the heads off a 3800 work as an upgrade? or will I be looking at more time and work? Really wish these engineers that built these cars would work on them just once to see how hard they are to work on at times. Time will tell........

 

3400 and 3800 are completely different engines. Outside of the coil packs, there are no compatible parts. The 3400 is a 60* v6 and the 3800 is a 90*.

Now, I've been down the road of a car that had the threads pretty much stripped on a plug hole due to a previous owner. And it happened to be a 3100 (same basic engine as the 3400 and the plug in question was on the back, closest to the alternator, worst spot possible). Problem was resolved without removing the head.
I bought a kit called "Save-a-Thread". I have seen in in the parts stores by different names.
I comes with a tap to re-tap the plug hole and you insert a heli-coil. I did this with the head on the car, I believe it had around 120K miles at the time. Key element is to dip the tap in oil, tap part way, remove any shavings off the tap, re-oil and repeat until eventually you have tapped the entire hole.
Follow the instructions 100% on the package and you have a 100% solid repair. I changed the plugs on that car at least two other times (it used copper plugs and they seem to wear out faster then any other material). And I drove it for another 100K miles until I sold it.

I hope this helps!

 

Helps greatly. Thank you. This one has 150k on it I think. Glad to hear I might not have to remove anything.