Damn I wish I would have known that ahead of time, because I got half a sheet to gusset the frame horns, ao I'm gonna end up having more then extra, I wonder if thats even going to be thick enough for the frame horns.... I know FBI's website says their notches are made out of 10 gauge cold rolled steel. I havent felt good all day and ended up buying the wrong dtuff, I bought a full sheet of 16 gauge for tubbing my firewall and filling the floor after the body drop....