Pontiac Repair: 1999 Pontiac Montana, intake manifold gasket, pontiac montana

Question
Hello I have a 1999 Pontiac Montana 3.4L with 68000 miles and the intake manifold gasket is cracking and is starting to leak coolant around the bolts. My question is should I repair it or have the dealer? I have been told that it could be $500 - $1000 to repair. I have been working on cars for many years and feel that it is within my abilities but should the factory  be responsible with there being so many complaints about this. Also is there any concern that the gasket could fail completely causing all loss of coolant and overheating while my wife is driving? And is there any web sites that have in depth info, more than my chiltons manual?

Thanks Kurt

Answer
There are alot of problems with the intake gaskets leaking on the 3.4 and the 3.1, but the warranty is only good for 36k miles. If you feel that you can do it yourself, go ahead. Its not that complicated. I do recomend that you use GM gaskets and GMS sealer.
Yes, the gasket can fail and cause a major leak both externaly AND internaly.