Well I finally figured out that the noise that bugs the hell out of me at about 55 is not the exhaust. Everything points to the center bearing, including the vibrations. Will replaced the bearing and rubber mount along with tailshaft bushing in the near future. Still have some loud exhaust though. Replaced donut at convertor inlet, and replaced flange gasket at manifold to downpipe connection. Still have some louder than normal exhaust at cruising speed. Should a car that was considered a luxury car when new sound like some hopped up civic or accord? It has a cheapo muffler on it than it almost gone so I am considering getting a Volvo Spec. system and also replacing the cat and manifold. The car is an 89 740 with 112,000. The guy I bought it from has another 89 740 so I may have him take me for a ride to see how it sounds.