i'm having a delema with myself. I would like to play in some mud, but i would also like to be able do 85+ on the freeway. So why not do 85 on the way to some old dirt roads then do some rally racing in the mountains. Plus i've put to much money into this truck to go and buy a 2wd.
Your lift isnt so much the problem with stability as the tune of the lift is. If you have 3inches BL and 6 in the suspension, It "can" still be a stable ride. Having the properly sized and tunes (by tuned I mean properly matched front and rear )swaybars will really help as well as proper spring rates and shocks.( no blocks, washers, pucks, or 10 dollar discount spring clamps/spacers.) Something like a Custom Watts link for your lifted truck will also help. It will totally defeat any flex, but point being you can have lift and stability. Ive seen the F250's with 8+inches doing 90 down the freeway.
Another hinderance to higher speeds is tire size, whether or not your lifted tire size and compound will affect your fuel efficiency and spped capabilities.
Having a lower truck will help aerodynamically shield the larger tires. A perfect example is the humvees, they run like 38's and we run 80-90 MPH in the newer ones down the MSR (main supply routes) Keep in mind these trucks weigh in at 20k+. (not convoys, only the escort missions where the contractors dont wanna be out there anymore than we do.LOL) Ive considered the lowerd 4x4 as well.
NOw the controversy, the application your referring too RallyRacing. I dont believe that 4x4 is what you need. 4WD is more suiting, where your transfer case has a differential for torque splitting front to rear. (similar to the Auto4WD of the newer expe's and epxloders. The 1354's I dont think will hold up to 60+ on a gravel road full time.
Now since mazda makes the m50d I wonder if there is a way to adapt the Mazdaspeed6 AWD system to the 4.0 ranger. That would be sweet.