I hear a slight exhaust leak when I accelerate. Seems to be when the engine rotates due to the torque from hard acceleration. I have the heat shield off but can't see or hear a leak at idle or at higher rpms when the car is not in gear. I've been under it while it was up on ramps, and can't locate a leak. It does not have a flex section at the end of the manifold, which I understand is prone to cracking, but has spring loaded bolts holding the manifold to the exhaust pipe flange with the hard donut in between.

Does anyone know where these manifolds typically crack?
Does anyone have any tips for how I might find the leak?
Thanks. -Art

If you don't have the flex section and the noise appears to come from the manifold, then it seems likely there is a crack in a tube leading to where the tubes join. My local Volvo shop suspected this immediately though mine was in the flex. A decent Mig Weld person can fix it, though a visible lead on the crack is needed. Removing the manifold was not too bad on my 95' 850. Nuts at the engine side came off with a mild soak of WD 40. Lower manifold bolts came loose w/o issue after soaking but were harder.

You can try duct taping the family vacuum to the exhaust. Get some insense sticks and move them around the manifold. Any leaks should suck the smoke in quickly. This may look a little strange to your neighbors but if you're Catholic they'll understand.

Good tip, thanks! I'll try that but my concern is maybe the crack doesn't open until the manifold gets torqued. Still worth a try.
I'd leave it alone until it was bad enough to be easily found, but I have a state inspection due in June and I'm sure I'll get rejected for an exhaust leak. Don't want to replace the manifold unless it's necessary.