Can't have an AFX rotor as it is only available in the 88 size machine. Most likely has the specialty rotor which is recommended for beans. We have customers in our area running the 30' 1020 on 66s and getting along okay in irrigated beans.
Most everyone around here runs 22.5' or 25' on a 2366. In semi tough group 4's the other night, a 2366 and I were running about 3.7 to 4.0 MPH. I think in tough beans with a 30 you would be going really slow. Chads
Don't pussyfoot around. Get that 30' head. I know one guy who pushes a 36' honeybee in 60 bu._wheat on his.....same machine as yours although he is just a wheat farmer but I think 30 feet would suit this machine well in your crops.
We run a 25' 1020 on our 2366. If beans are mature and have no green stems (like after a heavy frost) then it would easily handle a 30' head. Otherwise I advise staying with a 25'. Even with a 25' I have seen times when beans were tough that I would have to almost crawl or not cut a full width. In normal conditions we can run 4.0-4.5 mph in 50-60 bu beans. After a killing frost we can run 5mph if ground conditions allow.