After the subframe is boxed, if your old mounts (to mount swaybar to subframe) look rusted and weak, you will want to replace them... However I'm thinking you might want to go with a subframe from bradness that has the double bolt brackets, instead of the OEM one side hooks the other side bolts. Even with a beefed up subframe the brakets (more so when rusted) want to rip out with a heavy rearswaybar. It seems the bushings for 21mm bars are a tight fit. You could have this happen.
