Some observations from a novice. Apologies if I seem like the boy teaching his grandmother how to suck eggs.

It's hard to top laughing when I see 4 bolts on the USA side of the adaptor & 12 on the British. I bought a mate around (retired Ford engineer) to advise on re-tapping some studs on the LR side & he was dumbstruck! "Why did the poms use so many bolts? Trade union dictates?"

Line up is CRITICAL. I tried to mate the motor to the GB in situ but gave up! AND that's with a rolling chassis. I had no luck on the floor either. I eventually mated them without the clutch- thats when I noticed the mainshaft butting up against the spigot bush in the flywheel- to get the procedure right & also found some of the 7/16ths UNC studs I had installed to replace dodgy 3/8th ones were a bit tight in the bell housing holes. The squared off end of the mainshaft is a big problem. Why isn't it tapered to a rounded end like I see on umpteen other vehicles?

For the future, if the eng or GB needs to come out, I can see myself removing both together. Possible? I think I read somewhere the Transfer Case may need removal. I'd expect to completely strip out the front.