Zilch,
In early July this year we towed our camper south to north along the entire length of the Bloomfield. Truck is a ML T/D Triton, all the gear fridges loaded roof rack and family of four. Camper is a fully loaded Trackabout Safari. We had three fridges, 125 litres of diesel and 130 litres of water on board. All we packed and heading north to the cape.
This outfit had no problems at all. Adjusted tyres accordingly we sailed up first gear about 2500 revs. One or two of the climbs we used low range mainly due to the track being chewed up. Loved it. Good luck!
Cheers,
Disco teddy.