If I book a flight with Qantas from Sydney to Dallas in August, is the aircraft likley to be a 747-400ER or an older 747-400?

If I book a flight with Qantas from Sydney to Dallas in August, is the aircraft likley to be a 747-400ER or an older 747-400?

100% Definatley a 747-400ER. The 747-400 can't fly the distance the extened range 747 can.

And in August you'll have a decent chance of an upgraded aircraft.

Thanks for your responses guys. Good to know :)

FYI

have just flown this route on 2 march

Were given (3 months ago) an upgrade to the premium economy seats (with economy service). After continuously checking for changes ( as a platinum member I know they change aircraft continuously) there were no problems - we last checked 3 days before flight

At check in in Brisbane we were given completely different seats and were told to "deal with it in Sydney "

In the first class lounge in Sydney (the sofitel staff who run this lounge are amazing) the qantas staff confirmed there had been an aircraft change - and hence the loss of those premium economy seats - both the upgraded seats and our original selected seats were now no longer available and we were given random seats which we had to fight to change to something acceptable 

So don't set your sights on the aircraft and configuration - they will change it !!!!!!

Good luck with your flight