Where is coil F located on Ford 5.4?

On a Ford 5.4L Triton engine (the common version of the 5.4L), the coil packs are not individually labeled "F". The 5.4L uses a system of two coil packs per cylinder, arranged in two rows of three on each side of the engine. There's no single "coil F". To find a specific coil, you'll need to identify the cylinder it serves and then locate its corresponding coil pack. A repair manual or a diagram specific to your engine's year will be necessary to make this determination.