If you use a old inputshaft or a clutch alignment tool when istalling the clutch assy,you will find that the trans will slip in easier. Loosely assemble the clutch on the flywheel,install the alignment tool of choice,center clutch disc and tighten the pressure plate bolts. I like to check around the outside of the disc and make sure there is equal distance betweeen disc and pressure plate. In the absence of an old input shaft or alignment tool. Put trans up in place have a helper push clutch pedal down.install trans,you may have to wiggle it a bit and turn output shaft( trans in gear for both ways of installing). I think your clutch disc is not centered and is the reason why trans wont go in.
