I ran a 1440 with a 20' 820 for 10 years. Bean yields in the mid 50s most years and wheat 60-70bpa. Usually about 3.25 -33.5 mph in beans, a little less in wheat. One thing that will help is open the concaves wider, a little wider than for corn, and crank up the rotor speed to 750 or so. Unfortunately I didn't find this out until I bought a 1660, added about 1_2 mph to cutting speed.