Yes. Save that whatever you do. I haven't found any replacements for that. I salvaged a few small pieces to replace the bottom part on mine. Maybe that has changed? Someone will chime in if they know of a source. I used Jims panels on my truck. They are fine. If you take it real slow and really look at the structure under the floor, those braces are spot welded to the floorboard. By finding and removing the spot welds, you can leave it in place and maybe save yourself some grief. They do have the flange in front.
There WILL be fitment issues but that is true for all patch panels. In my case, I had about 1/32 too much material on the door edge so it was hard to rebend or cut and reshape the door end properly. My suggestion is to do what I didnt do, and deal with the excess on the trans cover edge. Another really smart thing to do is measure EXACTLY where the bolt hole is for the cab mount, where the screws are on the trans cover, etc and measure from someplace that is repeatable once the floor is gone. It needs to be put back exactly where you found it. I would screw the trans cover on before welding and see where you are. There may be some head scratching, but it will be a fun project!
