[Oldbluoval]

Actually, the bottom edge is spot welded along the metal subrail with only about 1/4”@ 90 degrees. You can bend it up but be careful to not interfere with the body block
However you don’t need 1 1/2” inches…trim to 1/2” or so

Also, I’m not a big fan of replacing the entire panel. I generally replace only what’s required by rust or damage. but usually 2 to 2 1/2” in the well because that lets you above the top of the subrailI don’t cut out original steel unless necessary. But you’d have to match up the body embossings if you do it that way.