The third one looks right to me.
I put a '67 MC on my '66 Mustang and a '70-ish prop valve. The third one looks closest to what I did. The switch on mine was pointing up, the lines went from the MC into the top of the block.
I will try to get a pic of my setup for you tomarrow. It works fine for me, I just upgraded the MC to a dual for now, the Granada spindles are going on soon.