I would think you'd be figuring out axle up-travel either way... My thought was, to expound a little, to utilize the computer for a 2wd and graft in your 4wd sfa of choice... the computer would never have to know that front axle is there. Then with say, lockable hubs, you would get the benefits on pavement of the 2wd but still be able to wheel (with 35's+) when you wanted. It would undoubtedly take away the modern convenience of AWD, but if you still had the traction control in tact, it should be every bit as good as a modern 4x4 pickup on the roads.

I don't know too much about it, just brainstorming. I suppose if you're still making payments, it's not as practical an idea.