Ebay mechanical parts (i.e. turbos) are a very risky investment. They have been known to run for years with no problems, while others blow up within weeks. This is due to how loose their tolerances are...some bore sizes can be right on the mark while others can be way off.
Keep in mind that the shaft/turbines can rotate at over 100,000 RPM - that's nearly 2,000 times PER SECOND. I don't know about you, but I wouldn't want some poorly made chinese part with that much rotational energy and a high fail risk on my engine...worrying about a compressor wheel shattering and sending all kinds of nasty metal bits into my engine.
Exhausts are probably okay (i.e. downpipe and back) - but the exhaust manifolds - maybe...as they usually have weak welds and thin metal construction that can crack under pressure. If you want to brace them and reweld them, it may be worth it. I have seen quite a few threads entitled "hey look what happened to my SSA/CXR manifold, it exploded!" with some grusome pictures inside.
I would be weary, like I said many have had success, but fortune has also passed over many as well.
It's not unlikely to make 250hp on something as little as 8lbs, which is my ballpark of what it's going to be set at (link is now bad). I would be a little afraid to go that far on stock injectors, but that may be right up to the stockers limit. In any scenario where my engine sees the slightest amount of boost, I want to make sure there is enough fuel there so I would say if you DO go this route, get a set of 370cc or similar injectors, a walbro 255 and an SAFC or at LEAST an adjustable FMU (fuel management unit) and slightly retarded timing or similar. Better safe than sorry - the stock pistons are the weak link on these motors and running too lean or stock (non retarded) timing can be bad news if detonation occurs.
Modified by airman86 at 9:07 AM 1/10/2010