Aquabro,
You have plenty of clearance running 33-12.50s? You obviously are not articulating the suspension. Guaranteed they will rub when articulated off-road, especially on AR wheels. Both the 10" and 8" width wheels use a standard offset that doen't cooperate well with the Xterra suspension. I would recommend you evaluate some serious suspension and steering modifications if you plan on going off-road. Otherwise your friends won't be pleased with you when you start breaking stuff. Bring spare tie rods.