Dexcool and the gaskets don't get along. Ideally, you would like to see the upper and lower Intake Manifold gaskets have been replaced, along with the plastic upper manifold. The newer style gaskets are pretty well bullet proof. Hopefully, it has been switched over to the green coolant also.
Even if the car has not been done, it is not that horrible a job to do anyway. Couple of hours in the driveway (yes, I speak from experience here), and the parts are available easily enough. This is NOT the same job as doing it on the 3.4. The 3.4 is an ugly, nasty piece of work to swap over the same parts.
Other than that, no major issues. The 3800/4t65 combo work very nicely together and the cars are shockingly good on gas. Nothing particularly high tech, but competent.
Good luck!
