Big_Al
Guest
I have had both machines and the big difference was the cross flow fan was in the 1688 but you can put this in any 1680 also you had more horse power in the 1688. Some of the older 1680's had a IH engine in them and a shorter sieve aera if your dealer was trying to sell you one of these then I would tell him there is a big difference from a 1680. But if you compare a 1991 1680 to a 1994 1688 the only difference is the cross flow fan and a bit more power. They both have the Cummins engine. I think it was 1990 when they went to the Cummins engine and longer sieve aera.