Heres another thought, something my Chevy might be getting!
If you put a divorced transfer case like an SJ one behind the fronty TF case....you could get real clever
The low ratio would have to be the same on both TF boxes...
but heres the twist...
Run the front axle off the front output on the fronty TFbox...
Run the rear output from the fronty TFbox into the input on the divorced TFcase...
Run the rear output of the divorced case to the rear axle...
This would give you...
RWD High....fronty TFbox in 2h and divorced case in 2 or 4 h
Rwd low...fronty TFbox in 2h and divorced case in 4L
Rwd Double Low...fronty TFbox in 4L, divorced TF box in 4L and manual hubs unlocked (great for pulling heavy stuff on grippy ground)
Fwd high...fronty TFbox in 4h and divorsed case in Neutral (if its got a neutral)
Fwd low...fronty TFbox in 4L and divorced case in Neutral
4wd high...Fronty TFbox in 4H and divorsed case in 2H or 4H
4wd low...Fronty TF box in 4L and divorsed case in 4L
Now the really good ones!
Rear LOW Front HIGH...fronty TFbox in 4H and divorsed case in 4L....(great to get front tyres up something near vertical without digging the ar5e in)
Rear Double LOW and Front low...Fronty TF box in 4L and divorced case in 4L..as above but much double lower geared for crawling the front up stuff with out digging
The front prop output on the divorced case could be use to run an air compressor maybe so it keeps the tank full all the time switchable by selecting 4h or 4low on the rear case...think onboard air....or maybe an airbag over the rear axle to force it down and lift the back if you high centre or try and find grip in the bottom of swamp...or maybe 2 airbags to force rear articulation to help lift a front wheel...
Obviously the split ratio (front high rear low) selection would cause bind up on the flat, but picture approaching an obsticle that was nearly vertical...drive up to it so the front tyres touch...The next thing that needs to happen is the front tyres need to climb say 2 feet, but your rears are only gonna need to move less than a foot forwards as they do this...normally as the fronts climb the rears with dig or start to bounce, but select low front and double low rear and you will climb much better with little loss of traction and no digging, the rears will just keep the fronts pressed against the object as they scrabble up...once the rears reach the obsticle or the fronts break over the top, shift the divorced case back into 4h for equal gearing again...
This same technique could be used when doing turns up a slope..imagine you are running in a bog parallel to the bank and now need to turn left and up the bank...normally as you try and turn up the rear pushes you straight forwards and the front tyres slide sideways and you are still in the bog...select your split ratio again and the fronts will now climb out much better as the rear is just helping not shoving you forwards...
This instances where split ratio will be right handy are often the kind of stuff where the landrover lads win hands down with their centre diffs open with drive being proportioned where it is actually needed...
Got brain ache now...hope that gives you something to ponder on anyway...
