Finished Clutch / IMS Job, now have scary mystery squealing noise

[black_box]

Here's a question:

What physical changes in the positions of various engine parts occur when the engine is under load (either accelerating or being loaded at idle by the clutch)? That will help me to narrow down the list of possibly interfering parts. I am also planning to slip off the drive belt to rule out any bad accessories. The motor was running / sounding fine before this whole mess (other than a cold startup rattle that I hear is pretty common on older boxsters)