I run a 9760 with a 32 ft Shelbourne stripper head and a 635 flexhead. The stripper head in down wheat takes a lot of power and I could pull the motor down. I also smoked a rotor belt-(my bad-it stretched and got loose). This was in 80 bu Spring wheat. The first quarter of soybeans I cut were green stems and I could pull the motor down then too. After the beans dryed down, I cut 40 bu beans @ 5-6 mph. My best day was 240 acres in 11 hours, but my neighbor cut 2800 acres in 10 days. (He starts early-runs late-wet or dry-he goes)If you haven't been around the 635 head, you won't believe how good it cuts-not a bean on the ground. I am putting auto-steer on the combine and the grain cart tractor as we came close to the cart tire a few times-(dusty,dark,and tired!) I don't think I would opt for 9860, but if you do the big corn head (18 row 20" or 12 row 30") in 200 bu plus corn, then maybe the 9860 is the way to go! Good luck!