[cas3]

Sounds like an interesting project, but the basics are your trans is too far back if you dont even reach the pilot bearing. You knew that already, so the obvious is what is the depth of the bellhousing, and what is the depth of the adapter, and what is the length of the input shaft? That equation must be solved first. I am not an 8ba guy, but are there different depths available? The steel ones could easily be cut and welded to the required depth. sometimes we gotta do what it takes. In my foolish youth, I put a volvo trans behind a datsun 240z, in my 38 chevy. To do this, I grabbed the sawzall in the vise, shimmed up the bells with plywood, cut both bells, mounted one on the trans, and one on the motor, took it to my friend the tig welder, and I straddled the unit, wiggled it around until it felt like the center, and said "thats it, weld it". Not what I would do today, but in 1980 it ran coast to coast for many years, still on the road today at a different owner. Again, you have the measurements, do what you gotta do