With the guide pins, you should be able to stick it in till the disk engages, then with the clutch disengaged (tie the pedal down) drop the tail of the tranny a bit and a VERY LITTLE BIT at a time, raise the tail of the tranny and wiggle it side to side while pushing forward. I think it'll eventually drop in place. My engine was on a roller stand and I was putting the tranny in by hand (3 speed, though, so not so heavy). Once I got a prybar in the clutch linkage and released it, it dropped right into place.
Hope you can get 'er done soon.
