Complex sentence: It featured a series for Group 5 Special Production Cars, Group 3 & 4 Grand Touring Cars and Group 1 & 2 Touring Cars which ran from February 5,1977 to October 23,1977, and comprised 9 races in total.
Split into simpler sentences: It featured a series for Group 5 Special Production Cars, Group 3 & 4 Grand Touring Cars and Group 1 & 2 Touring Cars. It ran from February 5,1977 to October 23,1977, and comprised 9 races in total.