Both races were held at the Tanaka International Aida circuit ( now Okayama International Circuit ) , a 2.3-mile track in the countryside in Aida ( near Kobe ) , Japan . Both races were held at the Tanaka International Aida circuit ( now Okayama International Circuit ) , a slow , twisty 2.3-mile track deep in the countryside in Aida ( near Kobe ) , Japan .