your two biggest issues will be your springs and shocks. the 4" springs are big flex limiters. with that much arch they just dont like to flatten as easily as a 2" set. this is not the biggest issue as we all know that compression is nice but droop is where you really gain advantageous flex. again the high arch will debilitate you as the spring is, by design, at the end of its droop potential at near ride hight. anyone who says their 5" springs are flex monsters need to see what a lot of very capable leaf sprung vehicles can do.
if you are using stock shock mounting then you are wasting the potential a good soa has. in a jeep these, particularly the rear, are the biggest flex hinderances. rework these to allow for the longest shock possible. as you relive your suspension to move you will find more and more little things that hinder flex. the simple orientation of your shock eyes can cause premature binding. they need to be mounted with the eye perpendicular to the axle tubing. this is 90* from stock. every little thing helps. undo the spring clamps and this will let the leaves separate during droop. make sure our e-brake cable isnt hanging you up. a slightly longer then stock shackle also helps. i like them no more then an 1" longer. make sure your shackle move freely by hand. do not loosen them to 45ft/lbs. this is wrong. if they do not move freely at factory spec then they are designed wrong. rework them until they are right.
....and you are going to have to cut some of that sheet metal. 40s just wont fit into the wheel wells period. if you have space between your tire and body at full compression then that is waisted space.
-insert meaningless out-of-place political diatribe-