Use these cups to convert Ironhead frames that originally used forks with 7/8″ Stem to fork that have a 1″ stem. Use this conversion kit when installing a Big Twin or late Sportster 1″ neck fork assembly on your early Ironhead Sportster. Simply remove your existing cups and install these steel cups into your frame neck, and you’re ready for Big Twin forks. Includes cups, bearings and races. Fits K Model & Sportster 1952/1981 Installation/Removal tools available here: Steering Stem bearing Removal & Installation Tool Steering Race Removal & Installation Tool