An attachment for connecting a chassis structure to a hollow beam of a body structure includes a tube nut, a bulkhead, and a bolt. The bulkhead has a cavity surface configured to conform to a cylindrical outer surface of the tube nut. The bulkhead is disposed within the hollow beam and is attached to at least two walls of the hollow beam and to the tube nut. A first portion of the cylindrical outer surface of the tube nut is disposed in close proximity to the cavity surface of the bulkhead. A bottom surface of the tube nut contacts an inner surface of a bottom wall of the hollow beam. The bolt extends from the chassis structure, through a hole formed in the bottom wall of the hollow beam, and into the tube nut to connect the chassis structure to the body structure. The attachment may include a second bulkhead.