Did you put new fluid in when you changed the diff bushings? I just installed a bunch of Pfadt stuff(diff bushings, solid subframe mounts, trailing arms, rear tie rods, and engine mounts) as well but forgot new fluid so had to reuse what I drained and now I have some gear whine but alot of people on here say a fluid change really helps. Either the GM brand with the additive or something like Royal Purple which I bought but have yet to install. Also, give it some time, it settles in a bit as well.
