There are dozens of threads on this topic already.
You have a ball bearing R34 GTR, and you want to put crappy N1, bush bearing rebuilds in?
cheap, nasty, dont go near it.
Ok for the tightass R32 GTR owner just trying not to have a motor die, you are better off with Garrett -9s or similar if you are going to change turbos.
And same again - these have been well covered if you take the time to have a 5min search. Thread on the exact product not even 2 weeks ago.