One of the most common places for rust to occur on 53-56 Ford F100′s is the front cab corner, also known as the lower cowl. F100 Central offers 2 different cowl replacement panels. One is a full cowl panel that replaces from the cowl seam (around where the side mirrors mount to the doors) down to the bottom of the cab corner. The other cowl replacement panel is shorter and can be cut if you only need the lower few inches of the cab corner. Usually the very lowest 5-6 inches is rusted the worst, but sometimes replacing the whole cowl is necessary and easier.
This is the full cowl repair panel – Left side shown
This is the shorter style cowl repair panel if you just need the lower section
