This heavy gauge steel part mounts across the frame under the wood for support. Bolt holes in the cross sill determine the placement of the bed strips and wood. The bed strips and bed sides are bolted to the cross sill and the wood is bolted to the frame through the cross sill by the bed-to-frame bolts. Cross sill is sold with holes and includes brackets. Made in USA.
This is the front cross sill for 1947-51 GM trucks with a 9 board bed floor.