With the bumper loosely installed and all the bolts in place, you're ready to adjust. It really is all about bumper spacing. You want the same spacing between the bumper and fender on both sides, which will vary depending on which bumper you have-especially with a reproduction bumper. Spacing must also be uniform between the bumper and stone guard, which is tricky to pull off. If you must shim, use a flat washer between the wavy washer and bracket, never between the wavy washer and bumper. Count on bumper-to-fender bracket alignment issues and finite adjustment. This goes for Ford bumpers as well as reproductions.