I'm not sure what you are talking about. There are two brackets that hang on the back of the cab in existing holes where the seat back hangs from. The L shaped brackets I recall mount the pass side seat bottom. The driver's side mounts by itself and the side cover screws to the existing seat skirt. Here are some pics on a few sets, some documents from the assembly manual, and actually, some pictures of an installation done by M. Barnes.
http://rides.webshots.com/album/495363233gvGeFS?vhost=rides