I know nothing about turbos but my buddy is selling a precision buick turbo housing, its a 3 bolt that takes a stock style down pipe and has the waste gate hole which we had plugged but can be opened again if need be.
he called it a GTQ .85 a/r housing. It was brand new but when we put it on my street car it was a little hard to spool so we changed the housing.
let me know if this is what you are looking for,thanks