Long time lurker but I thought I would respond...
Think about how the stock shroud mounts at the bottom in the spring clips. I went to lowes and picked up some metal brackets 1.5" wide and about 3" long. I cut a two slits with my dremel tool on the bottom of the contour fan shroud. One above each location of the factory spring clips that the factory shroud uses. Then slid the metal brackets into the slots I just cut, mounted them to the contour shroud with nuts and bolts. Then slid those brackets into the factory clips, then at the top I used the zip ties to pull it tight at the top. The shroud is mounted so that it is flush at the top with a gap(bottom part of the radiator exposed) at the bottom. The brackets takes the weight off the zip ties so that the zip ties can do their job pulling it tight.
Barry