We run in beans, corn, milo, and wheat. I was told by my dealer to leave the rear blocks up. Then raise and lower the fronts as the book tells you do to. So far the only time I have to reverse the feeder house is when a clump of green beans do not feed well, usually when I just pull into an area or cut around a tight corner in a terrace. (or when I was trying to be a smart but and run 6 mph with our R42!) I love the hydraulic reverser on this machine. Beats the pants off the CIH 1660 starter motor to reverse the feeder house!!! I have not noticed any wraping of the crop around the middle feeder house shafts leaving the upper block up, we also have shocks on ours. Hope this helps.