Ball joint replacement
 

Hello all, it's been awhile. I have an 02' 2dr. 4wd zr2. Tires were wearing funny so decided to replace ball joints. bought duralast joints from local store. Worked on upper passenger side today. For some reason the thin flange that helps protect the dust boot will not go through the top of the hole. I noticed there is a groove in the bottom of the new flange. My question is, can I install the thin flange on the underside of the upper control arm or does it have to go through the top. Thanks in advance.