Clecoed the left LE to the spar and set the tank in place. Installed the flange screws and checked the fit of the LE-to-tank skin joint. Used the cordless drill and a 12"x3/16 bit to back-drill the z-brackets thru the spar. Dismounted the tank and filed the tank skin to meet the LE skin. Set the tank back on the spar and drilled the joint plate to #12 for 8-32 screws.