2004 Explorer Powertrain Swap

I have a totaled 2004 Ford Explorer frame and powertrain. I'm planning to
drop a 1949 F1 on top, but that is irrelevant at this point.  The model is 4x4
or AWD, I don't know which, however there were originally three buttons to
select which I believe included a 4 low if that helps rule out AWD.  

Problem one, there is no computer, I have seen computers for the engine
only, a 4.6 but this vehicle had wires connected to everything, even the rear
dif.  So with an automatic transmission and electronic transfer case, can I
get a computer, or multiple computers for the various pieces to get this
running.
I would could remove the motor from the transfer case and do some kind of
manual system if the 4x4 auto cant be made to work.  As this is going
under an old truck and there will be almost no weight on the  back I would
love to have the AWD transfer case if it would bolt up, or I may put a
viscous coupling in if I don't have the AWD version.
Problem two, the wiring will all need replaced.  

Question 1 : What do I need, wiring harnesses and computer wise do get
this thing rolling?  

Question 2: could a AWD transfer case be swapped in if I don't have it, or
could a viscous coupling be added to the 4x4 case?

Question 3: As this is going into a custom vintage vehicle. Emissions are
not an issue, how could the computer, if OEM, be adapted to ignore post
catalytic converter readings.

Thank you for any help with this!