Parts and Service | Case IH Only genuine Case IH parts are made for your machine and designed for peak performance. We engineer, manufacture, and choose parts based on the strictest design and testing standards. And the Case IH Parts Store has made it easy to help you find the part you need.Visit The Case IH Parts Store · Search Case Parts · Dealer Locator · Tractors · Shop by Categories Case IH Combine and Harvester Manuals | Farm Manuals Fast Case IH 1660 Combine Manual. This manual is the 350 page operator's manual for Case IH/ International 1660 combines. Covers all serial numbers. This manual contains tons of information on trouble shooting, seed loss tables, and more. If you are combining with a 1660 machine you need this manual!