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