These are diffs off a 4.5 and will take my GQ centres in 4.6s no trouble at all. Straight bolt in. If you grabbed a set off a zd30 you'd get 4.3 centres and your lockers would go straight in. I assume your running 4.6s already though? Although your rock hoppers would probably mean some 4.3s would be sweet.

Is it only the Ute Cab that is your issue?