For a better seal use Permatex Indian Head Gasket Shellac Compound or Aviation Form-A-Gasket sealant on the gasket and screws. Connect your in-tank wire harness to the fuel pump, making sure that the connections are secure. Route the wires through the pass through fitting being sure to leave a little slack to prevent strain or chaffing, Use a 9mm wrench to tighten the upper jam nut on the wire pass through in 1/4 turn increments until the wire no longer moves up and down. BE CAREFULL NOT TO OVERTIGHTEN DOING SO COULD BREAK THE FITTING OR CAUSE A LEAK.