With a 4.0/AW4 combo go with 4.88:1 axle gears. You could live with 4.56:1 but, 4.88s are the perfect gesrs for 35" tires on the XJ.
Brian "Buck" Buchanan, U.S. Navy Chief Petty Officer (RETIRED) - 87 XJ Laredo, Ol' Red - 8.5" Rusty's Offroad/Rough Country lift, D30 trussed and D44 high clearance shock mounts, 4.56's, Aussies, Chromos and Disc Brakes front and rear, JCR Offroad Belly Skid Plate and Stage 2 Rock Sliders, Off Road Fab Winch Bumper and Quarter panel Guards, Liberal Front Wheel Well trimming and Rear Wheel Well Cut N Fold, 35" Goodyear MTR with Kevlars, Cobra CB and AW4 First Gear Lock Crawl switch, SYE, Stock XJ driveshafts front and rear and Milemarker SEC8000 Winch.
91 XJ Sport (Old Gray Jeep) - Layed to Rest (04-01-13)
87 XJ Laredo (Ole Red) - (My Jeep)
87 XJ Base (The Boys Jeep)
96 XJ Country (The Daughters Jeep)
08 Dodge Charger R/T (The Wifes Ride)
04 Silverado 2500HD Duramax/Allison (tow rig)