Thanks for the reply, I can use all the help that I can get right now!
The problem (if you could call having a crawler a problem!) is that I have a dual-case crawler in the Xtracab (long bed chassis), but shortened rear and lengthened front drive shaft). The 4Runner is on a short bed chassis, no crawler...yet, so the driveshafts won't swap. I'll probably end up going to the 4.7:1 crawler gears, rather than dual cases in the 4Runner.
There has to be some transmission experts out there - please chime in.