Mondo, Your statement that the CR's class 6, 7,and 8 are all the same is NOT true. There are 3 different engines 458-476-629 cu in, 295, 330, and 370hp., two rotor sizes, 17" and 22". The seperator width is 10" wider on the 970, it also has 1705 sq in. more cleaning capacity (under wind control)and is 1680 lbs heavier. CHN discontinued the class 5, 920 which shared the same chassis with the 940 and 960. Info from sales booklet.