My other Early A ---65 Dart post
Here is the white 66 Dart parts car all jacked up in the dirt underneath my shade tree. Its rusted out in the front footwells so I'm cutting out the floor with the tunnel starting from the torsion bar crossmember. To the best of my knowledge there are patch panels available for the four corners but they do not include the section under the front seats or the driveshaft tunnel.
I pretty much need the whole thing front to back and left to right for my other 66 Dart as there isn't even any solid metal left to weld in patches. I've got some really good drill bits this time so no problems drilling all the welds and didn't even need a pilot hole.
I wasn't worried about drilling completely through the floor and goin all the way into the top of the rockers because the parts car is wrecked so badly. I did manage to not drill all the way through the torsion bar crossmember just in case I need it later. One all the welds were drilled out I used an old brake spoon to wedge between the rocker and the floor to work it all free. A bit of hammer and dolly will get it back in shape when its time to install.