Anything above 400+ runs should seal the deal for Australia, even 380-ish would do the job.
In the first inning, Aussie lower middle order did add 100 runs on the board, so they can expect the more or less same today as well, maybe bat till lunch and declare.
Not sure what will our shaky batting lineup will do in the last inning, looks tough atm. Need a brave effort from all units.