Haven't got to 50,000 miles yet as of June 2016. Has been a great car for me. Preparing to do some preventive maintenance. Since it is a Series II 3800, it has the plastic plenum/upper intake manifold. From the online reading I've done, the original upper and lower intake manifold gaskets should be replaced with the upgraded ones, and I'll replace the original plenum with an improved type with protection for the EGR stovepipe. Will also replace thermostat, serpentine belt, hoses, flush cooling system, etc. Any suggestions or comments regarding this will be appreciated.
2002 GM: Buick Regal (Silver)