We never removed any cage sweeps prior to shimming helicals by 1/4" along with green stem kit. Lately we have only been providing channel helical package. We have fine tuned the last couple helical packages with a couple steeper pitch channel helical. Just like Krawler suggested it is first important to prevent busting up crop prior chopper. We got by with all cage covers removed except one on each side of left concave arm and far right one next to right concave arm. We cut the ones imediately behind concave in a triangle shape (longer side next to concave arms). One step beyond this was to build a tin wall upward from left concave arm to area just beyond crown of cage. This helps prevent material from hanging over left concave arm area and eventially plugging a large area. We fastened the tin wall to the bolts holding thresher and seperator cage together. Hope this helps