I had a 1978 JD 7700 Turbo-Hydro all the rest was a very good machine . 216 and 643 heads . I wanted to buy a 1988 7720 T2 . The Deere dealers thought they were GOlD in 1995 , they were all asking $45-50,000 just for the machine . I had the 7700 sold to a neighbor and I was keeping my old heads . Got tired of their high prices and independent attitudes , found a 1991 1660 1200hrs ready to go for $5,000 cheaper , it had 30" tires , big bin ext. , incline auger , rocktrap and chopper . I'm a Deere Man and the Deere Dealers said " you wouldn't buy that " but I did , got a 1020 20ft and still use my 643 Deere cornhead . I now have 2600hrs on it . We do about 650acres corn and 250 acres beans a year . I have the standard rotor .Some say the sp rotor is better in beans but damages corn more , I don't know . After this season I'm going to rebuild the rotor . Far as problems , I'd say same things wear out as on the 7700 about the same time , 7700 I think was one of the toughest machines built . CIH is much easier to work on , much simpler than the 7700 and the 9000's are even worse . Thing I miss most is no variable speed on the head. If you have "ONE" rock in your fields DEFINATElY get one with a rocktrap , I get a 5 gallon bucket of rocks out of mine yearly NEVER YET have had one go through . Some say the rocktrap slows flow of material going in but I don't buy that especially after seeing the damage done to neighbors who don't have a rocktrap . Chopper I wouldn't be without either but it is like the rest you have to reverse or change knives every 1000hrs or so . My biggest complaint on the 1660 is the oil consumption 2 qts a day after 40 hrs on oil change . They say the Cummins engine uses that much normally and it hasn't gotten any worse in 6 years . The old 7700 would use 2 qts in 100 hrs , I just have to watch it . Chaffer area could be more, in 25% corn you have to run it too open and too many cob pieces come through .I like the 1660 and would buy another one , that's hard for a GREEN man like me to say but I'm satisfie with it, has enough power and fuel consumption isn't bad for what you get done . I ran on too long hope I helped . JIM
