This Systems and Procedures Exchange Center (SPEC) kit on retrospective conversion, which replaces a 1975 kit on reclassification, is based on interviews with and documents from Association of Research Libraries (ARL) members participating in retrospective conversion (recon). (Reclassification is almost always conducted as a sub-project of retrospective conversion.) The kit comprises: (1) cooperative network and utility documents on recon from the Internetwork Quality Control Council, the Research Libraries Group, Inc., Palinet, and the AMIGOS Bibliographic Council; (2) systemwide and individual library documents from Texas A&M University, University of California Systemwide Administration, University of California, National Library of Medicine, Joint University Libraries, and University of Colorado-Boulder; and (3) an excerpt from an ARL-sponsored study focusing on the development of cost models for alternatives to the card catalog. The concise summary that introduces the kit briefly discusses key decisions; planning concerns; and issues and trends, including the development of guidelines that can be applied by many libraries. (THC)