You'd be better off to drop the trans. out of the car. Install the engine and bellhousing in the car. Bolt the motor mounts fast, then you can angle the engine down to install the trans.

When installing the trans, it is best to have someone sit in the car and push the clutch pedal in. Yes I use an alignment tool, but if someone light (like my wife) sits in and pushes the clutch in once you have the input shaft through the clutch, it slides in much easier. There is room for fudging. When everything is tight, it has to be exactly right. You can push and push and use bolts to pull it in, but if you have someone on the clutch pedal, once things are lined up exactly it will litterally fall together. Just make sure you don't have any fingers between the trans and bellhousing. There isn't any gap once they slip together.