Oh, ok. If I were you, I would try to get the 4Way as close to the tank as you could, before going to your outlets. You would use less pipe and the water would not have as far to travel. Use 45s from the Dart to move the valve closer to the back of the tank. That's what I would do anyway.
I have True-Union valves on the input and output side of the Dart. You don't really want valves on the other side of the 4Way, because it is not good to restrict the flow and put back pressure on the drum. You can throttle the Dart back to around 400 gph with the output valve from the pump, if need be.