I would just advise you to take out the leaf packs and burn out the old bushings, maybe you could cut them out with a hole saw though, maybe not. But anyway I had to burn out mine. I used a propane torch from walmart. I replaced them with the bushings you are looking at and really have had no squeaking for about 500 miles or so.

My fronts were actually fine, but I replaced them anyway. I had no air tools just a jack and four stands,and it was a one night, sleep, then next morning job.