Sorry,I meant I re-placed the center section.It comes balanced,ready to go.Just put your original housings back on,careful to keep new rubber o-ring in place,snug the 10mm bolts just enough to be able to re-clock the housings on mock-up,remove turbo and tighten all bolts evenly,then install turbo.That is pretty much how I did it.Seem right?Only problem is upon start up,I can hear the turbo make a sound which sounds like to me the fins are barely rubbing compressor side.It is a much louder whine.After it gets hot the sound leaves and then you can only hear a whistle which kind of like sounds like a cop siren going higher until I let off a bit then the siren winds down.See,My last New center made same noise for a couple months then it quit.3,000 miles later it started blowing oil into intake side.I said CRAP,I need another turbo.Upon removing the turbo and inspecting it there was NO indication it had rubbed.Even a guy very familiar with turbos said he didn't see anywhere it had rubbed.1 more thing,When I put the 2nd new turbo together,I looked at the clearance between compressor wheel and housing,Pulling it side to side while spinning it and It had just like .002"-.005" clearance according to my EYEchrometer!Thats everything! Anybody think it will fail early?I am wary of it!