This Direct Sheetmetal Replacement 1928-1931 Ford Behind The Seat Pan- #3 Pan- '28/'29 ALL,'30/'31 Sedan. MEASUREMENTS: 18.5" X 36-7/8" SQUARE. The Behind The Seat Pan is manufactured from 16 and 18 gauge cold rolled steel. It includes required mounting hardware and complete instructions. All of DSM parts are designed to make installation simple and comfortable in your home shop or garage.