Any name brand oil that meets Kawasaki's specification will do. Modern oils are better than the oils on the market in 1982.
I used Valvoline full synthetic hipoyd gear oil in the specified viscosity in my two Concours. About 90,000 trouble free miles between them.
1982 KZ1000 LTD parts donor
1981 KZ1000 LTD awaiting resurrection
2000 ZRX1100 not ridden enough