Clutch issues. Can't put gear in while engine running

Yep, that is the conclusion... a finger hit that spring. I will say this: The OP is doing a good job of looking at all aspects of this, and is bound to get this sorted out. That Z-bar bushing is.... um, interesting!

I found some info on the PP: it appears that the PHT C1647 pressure plate was from China, sold though Autozone. Nothing worth keeping IMHO....
Flywheel thickness 360 V8=clutch issue?

Is that the pilot bushing? Looks too big buuut....time for the clutch to come out!