This is what I have learned about cutting wheat,HRW_HRS with a 9750_936draper.Rotor 950-1000,keep it full,concave 18-25,(small wire)I have run many acres at 20. Keep the chaffer tighter than the book says,I run it around 12-17.Keeping it tight blasts more air threw the fixed chaffer in front.Fan around 1250 in heavy wheat.If you have white cap problems put two coverplates on the last two sections on the middle concave,thats were the returns dump.One thing I learned is that the setting that deere put in there book is usually wrong.I am very impressed with it.It's a wheat eaten machine.