I suggest you put in a set of chrome alloy standard rotor bars. They are made from the same material as the Gorden Rotor Bars. The ones I sell have a protection ring nearest the bolt head to protect the bolt from wear. These bars will out last ductile iron by five times. Unlike chrome plated bars, where the chrome chips and flakes off, chrome alloy does not flake off. No sharp edges develop like chrome plated bars do. Also, consider a set of chrome alloy impeller wear blades made of the same material. I have one set of helical concaves left for a 60 series combine. They are Australian made, to my specs, for use in wheat, beans and corn. They have proved to be less susceptible to plugging and have great capacity to reduce rotor losses, especially in corn and milo. They thresh very well in tough wheat. You are welcome to phone for a more lengthy discussion about your combine. Phone: 1-800-745-1680