since this post started I have called my mechanic at the local Nissan Dealer ( 18yrs there as Nissan Master mech ) and two other Z specialty shops down here..exactly the same story as you describe. I would bet If I call SGP, Paul@Avalon and any other Z shops I would get same info. Spun Bearings are very rare and no correlation from the three shops I called to ud pulleys from any of them. I will call the others when time permits.
1990 Twin Turbo 5spd Stage 12+ 1999 Maxima SE 5spd ..also performance modded