64 Dart Gt 4 speed won’t shift into gear ??

I’m really hoping it’s not the dam pilot bushing.
How was the bushing installed and checked for clearance for the .750" input shaft?

Might you have allowed the weight of the trans to hang on the disc spline and possibly bend the hub?

BTW, the FSM calls for grease in the bushing bore prior to installing the trans.

I don’t know why but putting back the the second time was a pain in the butt

They can be especially hard if the disc isn't lined up, the bushing is too tight, the bell not dialed in, or combination of all.