Is it going to be run offroad or is this for looks?
The reason I ask is because you said you have a LP D30. You're already running on the weak side of the gears and as Eddie mentioned, the deeper the ratio, the smaller the pinion. Take the low end torque of the 4.0, combine that with low range and the likelihood of gear damage increases tremendously.
If you do want to swap out the front axle, an HP D30 out of a Cherokee is a worthwhile upgrade simply because they're cheap and you get the added strength of running on the correct side of the gears up front and you get to bring that driveshaft up some. Stay with the 4.56 because they'll be stronger than the 4.88s. Even consider 4.10s for the best mix of gearing and strength. Stock shafts, especially if locked in the front, won't hold up to much shock load from the larger tires.
A setup of a HP D30, chromoly shafts, 4.10 gears, locked with 35" tires and stock wheelbase worked very well for me. It was pushed to the max of it's capabilities running that equipment and my skill as a driver. The 4.10s left a little to be desired on the highway, but held up well when deeper gears would have left me in a pinch on the trails.