I will check
For fitment in a Landcruiser, 15B will fit an H55F (if it has the correct B input shaft) if you have a bellhousing and *all* associated components from a B series landcruiser. NB: BJ4X cast iron bellhousing and BJ7X alloy bellhousing set the gearbox at different angles.
There are various flywheels (8 bolt), the larger ones from a coaster with 2 piece bellhousing won't fit, I'm not sure what size the megacruiser ones are. I ordered a new flywheel as mine is a coaster engine and too large.
Note: 15BFT is usually mechanical inline injection pump (PCV hose comes out side of rocker cover like a 15BF), 15BFTE usually rotary electronic (PCV hose on top of rocker cover as per images above)
From what I have seen of pics online, the military megacruisers seem to be 15BT (8 valve version), 15BFTE and NO4C. the 15BFT seems to be limited to the Coaster bus.
I will be doing a write up in a thread soon, as I get mine put together and installed in a BJ42