I removed the tank from the spar and clecoed the end ribs back on to the skin, see image 1. The Z brackets were position identified, engraved with their position and deburred.The inboard most Z bracket gets attached to the spar by anchor nuts attached to the aft face of the spar, image 2 shows their installation, where as the remaining Z bracket will have anchor nuts attached to the bracket itself and be bolted from the aft side of the spar.