Its the same switch. The button is on top, surrounded by black plastic. It is hard to see. I might be off on the dimensions, because I only looked at mine once when my selector switch went out.

If I remember correctly, it is wired in series. Ignition, relay, inertia switch, selector switch, then pump.

If it has two wires in one plug going into the bottom of it, you found it. Look closer at the top of the box, there is a black ring, inside that ring is the switch. If you push it down, it shuts off the fuel, recommended to change filter, and then take a screwdriver/key and pop it back up.

If you still can't find it, let me know. I'll see if I can take a picture of my truck tonight and post it tomorrow for you.