If the engine starts up without a gear being engaged and doesnt move and the pilot shaft doesn't howl, i have doubts it is your pilot bushing if you installed a new one. Could be, but not probable.
Linkage or fork could also be the culprit.
10 or so years ago I had a not obviously cracked clutch fork that flexed and wouldn't push in the three finger clutch pressure plate to release the clutch.
Most recently I had an issue with the old original clutch linkage nut would slip on the adjusting rod and become un-adjusted when the pedal was pressed.
To troubleshoot both took me being under the car, dust cover off and throwout bearing adjusted. a person in the driver's seat to step on the clutch. Watch and see where it gives.
Edit: I've also had welds go bad on the torque shaft (zbar to chevy folk) and had it flex, same thing, pedal pressed and no disengagemnt.
