Hi Mr. BA,
Since converting the two remaining B747-238SCDs to full passenger fit Qantas relies purely on underfloor for freight carriage in the company's aircraft. Over the years U.S. based freighter aircraft have been leased by Qantas to operate transpacifically (the old combi route). These include Evergreen B747-100s and Gemini DC-10-30s.
Hope this helps,