I made a flap drive alignment tool out of some scrap aluminum. I drilled a pilot hole 17/32' in, and 2 19/32' up from a 90 degree corner, with square edges. This is the location that the hole in the flap drive needs to be when finished. I then used a cleco throught the flap drive plate, through a collar I use for extending my rivet heads in tight spots, and into the jig I made. Once all three are assembled you just keep the edge alond the flap rib, and the lower edges aligned and you have a flawless way to keep the hole aligned. Now you can just move the flap drive plate around to the position you want and clamp it in place for pilot drilling. I drilled a few holes and installed clecos before I finished the drilling. It worked like a charm, and it is usable on both left and right sides.