Your Explorer has a 8.8" rear axle and a DANA 35 in the front TTB. I've seen lots of explorer's on 33s and both axles according to one of the 4x4 mags I read (I can't rember which one) will hold up to 33s just fine. You may want to upgrade your brakes though. I would also swap the Ford hubs for the Warn replacements if your going to use 4wd alot.
Dennis

95 Sportage, gone but not forgotten.
98 Jeep TJ, 4" Zone springs with RC Long arms, Ford 8.8", 4.56 gears & Detroit locker rear, D30, 4.56 & Detroit Trutrack front.