I have rotor bars modified by Siscoe's metal clinic similar to the Trimpe. By cutting down every other tooth, corn and soybeans aren't pinched. I run near 0" clearance in soy beans with very few splits. I also have the "green kit" of helicals on top of the cage. Siscoe prefers bars worn down so he can build up with carbide. He then matches bar pairs by weight and position on the rotor. One mistake I made was also haveing the Reverse bars built up, now I can use them on the floor. I run corn and soy only, can't comment on smaller seed grain. If you load the engine the same, your bu_hr will increase, with less cracking. I'm well satisfied with the modified bars, less hp_bu.