Mounted the clecoed tank and ribs to the spar, drilled the outside rib holes in the Z brackets. Removed the tank minus the outside ribs and the baffle and final drilled all the Z brackets holes matching with the baffle holes. This is a very accurate way of match drilling the holes for a perfect fit. Next was to manufacture the joint plate W-423 so the tank and leading edge can be joined. As usual the process of alodining and priming was done.