We harvest just wheat and flax with our 9600 and it does an adequate job with a few unthreshed kernals in the tank. I just tore into the combine and found it to have 7 of the first concave openings to have filler plates. Is this really necessary? I have been getting alot of grain on the walkers which limits my speed. I was going to leave just 3 in and give it a try. What do you guys run in your combines? Thanks!