By now I am sure you have heard about the Dex-cool issue involving the need to replace the intake manifold gaskets of GM cars from 1995 to 2004. And you are also aware that GM lost a class action settlement ( http://autorepairarticles.com/category/recalls/ ) . If you had this repair done, you have until Oct 27, of this year to get your money from GM. Follow the link posted above to get the required form and read the entire issue.
What causes the issue in the first place?
The Dex-cool turns acidic after a couple years and creates havoc on you engine gaskets. it actually eats away at them like cancer. Now you might want to know do you have to use Dex-cool. The answer is No. But in order to use the old green coolant you must flush the coolant system completely as you can NOT mix green and orange coolant or it will gum up your coolant system.
How do I avoid problems on my new gaskets ?
Have your coolant changed every 2 to 3 years as age is important for this and not so much mileage.