prodigal son

Hey guys, I've seen lots of swaps into the late model B2000/2200, and of course there's the early REPU, but I have found exactly zero info on the middle child. I'd like to swap in a 6 port 13b and leave it pretty much stock. No turbos please, this truck is going to have to work for a living

Now I understand that I can fit an FB 5 speed into the truck by using my B2000 tailhousing. Is this correct? Can I use an FC smoothcase or miata trans as well? Will my stock speedo drive work with the 'guts' of another trans, or do I use the drive that comes with the new one?

The stock F/MA motor is a front sump, with the engine crossmember going under the rear of the motor. Is there any such thing as a "front sump" oil pan with rotaries? Do I just need to mod the stock crossmember?

Also, if anyone knows the answer, I've heard that the innards of the GSL-LE diff (with the LSD) will swap into the truck axle. Anyone know if that's true?

I'm sure I'll have more questions, but let's start there