Combines 9610 chopper

Do you have the tailboard all the way up and the chopper in high speedIJ You can get taller chopper vanes for your combine. I have seen those on the 60 series. That should help some. You could also take a pair of channel locks and bend some of the vanes out more.

Redekop has a rotor upgrade for better spreading and finer chopping. Of course they will sell you a complete new chopper too.

This might work it might not work. Take a square piece of poly or sheet metal and cut it into two triangles and bolt it into the corners on the under side where it discharges. That might help carry it out an extra foot or so. Also some have used a stalk chopper style knife on the last couple of rows of knifes on each side to get a little extra width. I can't say if it will work on a Deere, but most choppers are built by one or two companies so....

Redekop MAV choppers are the only way to go. I use one in my 9600 and can do over 30ft of spread. I just dial it in to what specs I need. Any other chopper simply does not create enough wind to spread period. Use tailboard vanes from the 50 series conventional. This will give you more control over your spread pattern.