No. It's a heavy panel that runs from rocker to rocker following the contour of the floor and tranny hump. The x-brace bolts to it.
Ken, this can only be found on a parts car.
However, and other may/hopefully will chime in. Perhaps you can achieve the strength with welded subframe connectors and then have some diagonal bracing added side to side. Otherwise, hopefully some parts places like Denny's, Rick's Camaro Specialties, etc can source or find one. I'll take a pic tonight of one I have if that would help.
69 RS Conv,355,M20,4.10's and I don't worry about stone chips ( yet ).