Over nearly 30 years of combining I've tried many, many modifications that have been on the market. I'm supposed to be retired but keep on doing custom combining because I like runnin 'em. Most effective & best mods I've tried so far are: 1. 18 Gordon bars installed on front of rotor, standard short bars on the remainder. 2. Air-jet chaffer. This is probably the single most effective modification I have ever used. 3. Loewin concaves w/shock springs installed to protect from rocks. They're great!

I combine a large variety of crops from wheat to garden bean seed, corn to buckwheat and small vegetable seeds and grass seeds.