#1. Left.E250. PartQualifier: #1. Right.E250. Upper insulator bolt. A threaded rod with a drive head (such as hex, 12 point, torx, etc.) on one end used to secure the Skid Plate to it's Mounting point. Body Mount Cushion Bolt. Frame Rail Bolt. and Washer Assembly. and Washer Assembly - HEX. HEAD. Body Cushion. Frame Rail. Powertrain Skid Plate.