Australian🇦🇺 men's track records/bests still on the books from the 1980's :

300m 31.88 Darren Clark 30-Jun-86
400m 44.38 Darren Clark 26-Sep-88
4×400m relay 2:59.70 Australia 11-Aug-84

20,000m (track) 58:37.2 Robert de Castella 17-Apr-82
One hour 20,516m Robert de Castella 17-Apr-82