Sub frame Connectors: 67-9 F Convertible onlyThe performance Sub Frme connectors for the 67 9 Camaro or Firebird were designed to add strength and ridgidity to the suframe to reduce body flex.. expecially in the convertibles. These are the best powder coated. mig welded steel connectors come in black with polyurethane fron body mounts. Installation of hese connectors does NOT require modificati or cutting of the floor boards. The rear mount s a weld in shile the front is a bolt i with the option