Originally Posted by RobBeck
The stock turbos have studs and long nuts as pictured from the factory (those are just the OEM replacements). Typically they are all reusable, some may say to replace the nuts but I dont think its required, although they are not expensive so its cheap insurance to replace them. I would at minimum suggest buying several studs and nuts though (maybe 4) as sometimes when you remove them they come out as one. You could also just buy 4 or so studs and all new nuts (16) if you want to play it safe.
I had to replace my nuts to bigger ones after I felt the power.