This has been such a big problem for so long now I doubt I'll touch on anything that hasen't been seen before but I was looking up my friends Alero 3.4 and I stumbled (always how I find interesting info) across a few web pages dealing with it. One had an interesting letter a guy got. You can see it at
http://www.gm-v6lemons.com/PONTIAC.JPG its huge so you may have to save it and view it otherwise, or maybe thats just me. Notice it only talks of 2000-2003..Also as you can see from the link, http://www.gm-v6lemons.com is another place to check out. Also it seems aparent that GM just has an intake problem with nearly every engine it puts out. Several have gasket problems to include the 3.1 and 3.4, I think I remember hearing about the 2.2 also. Interesting how its so much larger than just the Series II 3.8 and yet very little is done. I have read about secret warranties that extend to the intake related problems only, they're just not required by law to tell you about it.

Most of the 60° V6'* had head gasket problems. They used cast iron blocks, with aluminum heads. The heads are prone to warpage. Then the gasket blows under the pressure that gets by.

At least the VinK was easier to fix, and we have cast iron heads!