Early ford tin pans had steel bungs or nuts welded inside the tin pan. Sometimes the pan internal (bung or nut) is too thin to drill out so we restore the threads by reducing the stock 1/2-20 size to 7/16-20. The hole must not have had any oversized drain plugs used. Kit only includes 2 driver tools and 5 inserts 07629 and 5 drain plug 10765