Assembled right tank with clecos. drilled one #12 hole in the center of each z bracket. bolt brackets to spar, centered with T square, and drilled the other 2 holes. Drilled and countersunk Z brackets for nut plates. Prime brackets, and installed nutplates. Bolt Z brackets back to spar, and layed tank in place. Drilled the inboard tank to Z bracket. This is the only one visible. Removed tank, and back plate of tank,a nd drilled the rremander of the holes to Z brackets. This process was confuseing, and took time to figure out what they were trying to tell me in the directions.
