I swapped in a Chrysler 825 rear axle and did a disk brake swap. So far I have no complaints; I can stop on a dime & give you change back! Bubba68CS is right about the proportioning valve too.
MODS: 2.5" Rubicon Express lift, 1" lift greasable shackles, POR-15'd new frame, Chrysler 825 rear end w/355 gears and disk brake swap, solid front axle (no more vacuum!), herculined tub (interior & bottom), Dunlop Radial Mud Rover 32X11.5 R15 on black steel rims, custom hi lift jack hood mount, Ramsey 8K winch, and AEM Brute Force air intake system.
Custom rear bumper in progress, Rock sliders on deck, and then front bumper...all fabricated by...ME!