manual tranny bellhousing won't quite connect to engine

[mattfranklin]

Stock sm465 tranny.
Stock iron bellhousing.
Stock-style Zoom clutch, throw-out bearing, and pilot bushing.
Stock 350 engine.
Bellhousing installed to crossmember.
Tranny installed on bellhousing.
Trying to get the engine in it.
Have a nice OTC leveler.
There is still about a one inch gap between engine and bellhousing. It just does not seem to want to go in. I don't want to break anything. Should I just keep twisting and jiggling things? Or pull it apart and look? What should I look for? What is likely to be wrong?