Hi John, I've recently dealt with a wobbling crankshaft serpentine belt pulley in my 2001 2.7, and was surprised to find very little elsewhere documented about this problem:
http://986forum.com/forums/performance-technical-chat/67798-noticed-some-wobble-crankshaft-serpentine-belt-pulley.html
I replaced the old (bent) pulley with the newer (straight) one, and while this managed to correct the serpentine belt vibration and runout, inspecting the pulleys more closely on a surface plate revealed troubling observations they they might have not been very well balanced when originally manufactured. The newer replacement pulley I stumbled across put on had thicker dimensions, so it gives me some hope of lasting longer.
Nice job onserving your serpentine belt also has runout. I suspect this "bent crank pulley" problem may be a whole lot more common than most people here realize!