Is my H1c screwed?
 

Got it a few years back, looked like new in Holset box....sat on it til I could use it. 1200 miles on my new build and it's smoking now. Took it off and when I blow thru the feed fitting (me..not compressed air) I can hear air hissing thru the turbine side. I'm thinking that's probably bad news? Didn't notice if it's coming out of compressor side too, but I could see a little spray of oil in the turbine. took the housing off and can see what looks like evidence of oil passing in. Not major, I don't think, but I don't have much turbo experience. Not running any oil restrictor. LS vtec/ gsr oil pump. Never measured oil pressure. I'm wondering if a restrictor might save it?
If it needs new seals, I think I could do the rebuild, but at what point do I stop to have it balanced? It's my daily...I'd really like to get her going again soon. Please help with your Holset skilz

Use a restrictor and make sure the return line is good. As a $5 fix, I would do that before a rebuild.

is your return line pointing straight down? and the return is gravity fed i.e. no pressure. so it has to be above the oil line in your engine.

Well to tell you the truth boss, every time you rebuild a turbo your going to need to get the main shaft balanced with the wheels and all on it. Your oil seals on that beast are toast, should have ran a restrictor on it, so it is time to replace the seals and while everything is apart you might as well do a full rebuild. Holsets are easier than all hell to rebuild so go at it, you can get the rebuild kits for next to nothing now a days, but I would highly recommend taking it to a professional to get the whole beast balanced out again, other than that you can just run it all smokey all the time. But to do that would be wrong, and I can not advocate not fixing what needs to be fixed. As I always provide in my advice, get it fixed and do it right, than everything will be just fine for you.

Junior is correct, you need to have the oil return line pointed downward with no force acting upon it, or it will build up back pressure causing, guess what, blown seals. Atreidies is on the right track, but I am sure you would have seen a bad line dripping on the ground, I think he meant to say that you should make sure you have the right size oil line do it is not restricting the flow causing back pressure and guess what again, blown seals, -10 at the minimum IMO.