c100driver, the B748 is designed to carry a full payload 8000NM which is why it originally was proposed with a shorter fuselage than the B748F. When Boeing's wind tunnel testing and computer modeling revealed that the new technology would perform better than predicted they then revised their offer for the pax version to have the same fuselage as the freighter and still retain the 8000NM range. It would do SYD - DFW with a full payload - a very attractive aeroplane. The four engine config would mean no problems AKL - Sth America and HKG - LHR (high terrain). The main reason why Air NZ probably won't buy it is because of the high cost of having an extra fleet in relatively small numbers. Generally, a fleet of less than 12 means that the operating costs are significantly higher - mainly due to to the spares inventory and other maintenance issues.