can BB car 727 be installed in 4x4 w factory 360?

OK.

So, the whole trans from a BB motorhome excluding the tail shaft housing will essentially hook into / bolt to the transfer case of a 4x4 housing?

I've done this a few times in the past. YES it can be done. Since motor home 727 are easy to come by, I have used the output shaft and used the trans to transfer case tail housing. and have made a 4x4 trans out of car 727's and motor home 727's. Let those who say it can't be done say what they will. I've done it successfully.