Great cars, but they do rust. First thing to do is drop the tranny pan replace filter and refill with maxlife ATF and a bottle of lubegard red. do it every 30K, the life of the 4T60E hinges on that.
2nd replace the upper composite intake manifold. With so few miles it probably hasn't eaten a lot of coolant but if it hasn't been replaced already its only a matter of time.
Replace the lower intake manifold gaskets and the composite coolant elbow with an aluminum elbow, below the map sensor on the passenger side above the water pump most likely it will be broken anyway when you remove the lower intake manifold. and of course drain as much of the dexcool as possible and replace it.
Other than those things a W-body with a series 2 3.8 will last well passed 200,000 easily