Countersank (sunk?) the screw holes for the #8 screws that will attach the wing tanks to the spar flange. The pilot guide was helpful. I found that if I didn't use it, the holes are not necessarily prefectly round. It was very tedious, cleco the guide, clamp the guide with two 1" cleco clamps, uncleco around the hole, countersink the hole, remove and repeat.
