Smoking Behind Engine

My 92 Park Avenue has another problem. Smoke comes out behind the engine. On close examination I find that the oil is seeping or leaking down the exhaust manifold. But the smoke appears to come out at the linkage between the exhaust manifold and the exhaust pipe. That seem strange making me think I had a exhaust leak in that linkage. Then I remembered that while fixing my water pump I cleaned the engine and whatever oil was on the manifold was washed out. What is smoking then must be the oil accumulated in the gasket in the linkage that did not get washed out. I am assuming that the oil leaks from the valve cover gasket. Do I change the rubber gasket or leave it alone and just watch my oil level frequently. It has over 200,000 miles.

Valve cover gaskets do occasionally go on these engines, I'd reccommend changing both, just for good practice.