67 PICKUP floor pan help

[Caddylackn]

There are two different type of panels. There are replacement panels. They require full or partial removal of the old panel, cutting the replacement to the exact opening size, and full perimeter butt welding to the old metal. The replacement panel may or may not be an exact duplicate in the center of the panel but should match up around the edges. The exact replica OEM replacement panels should be an exact replica, and thus they are the most expensive.

Then there are repair panels, which are designed to go over the top of the old panel with a 1" or 2" overlap and the center of the old panel removed. These can be lap welded or spot welded in place, then seam sealed around the edges.

The repair panel does not fit like a replacement panel, since it has to fit on top of the other panel, the radii of the curved areas are larger. They don't line up well if you try to butt weld them in like a replacement panel.

It looks like you have a repair panel. You should be able to make that one work, I would trim it to fit over the top of the old panel, then decide where to trim the replacement panel so you know where to cut out the original panel so you have enough over lap. Then trim it to final size, then fit it and trace around it to transcribe to the old floor. Then cut your old floor out, leaving 1" -2" inside the line for lap. Then I would drill 3/16" holes in the replacement panel about 3/4" from the edge every two to three inches around the perimeter. Then you can throw a few self tapping screws around it to hold it in place for welding and keep the panels tight together. Then tack weld it to the old floor through the 3/16" holes, then remove the screws and fill those holes, then seam seal the perimeter, then paint, your done. You can get a decent fit/finish with a replacement panel, but it won't look factree when viewed under the car.

The beauty of a replacement panel that is overlapped is that you can get one of these in and welded from start to finish in a few hours, compared to many hours for a replacement panel with a full perimeter butt weld and ground down and finished. If the truck has carpet, you will never know which one you used. You should seam seal the bottom if you can or use a heavy undercoating on the lap weld on the underside so water doesn't get in between the panels.