Next I set the cases upside-down on a blanket on the floor (don't tell my wife where the bed cover went!), and then set the rack in position upside-down on top of them, using my previous chalk marks as a guide.
I used a square and level and a piece of aluminum straight-edge to get everything lined up, square, even, and where I wanted.
Because of the shape of the underside of the rear rack, you don't have complete freedom of where to drill the holes for the mounting bolts.
I used some nuts (red arrows) to lay out where I wanted the bolts to go, checking to make sure there was clearance for the nut while locating the fastener in an appropriate spot on the case (i.e. reasonably spread out and far enough from the edges). |