Car power/start troubles

The car is new to me, a 71 Duster and I just did a /6 to 400 "B" swap. I have a strong battery. A good cable to it. No power anywhere at the relay. I turn the key and get nothing. (Starter will turn when I use a screw driver to it but not at the relay)

My fuse box is live but have no power through out the car.

I do not know the pathways the energy takes, so, where can i start the tracking?