The Wicked Wheel site says you can just install it and run. They say it is balanced. Now, the question becomes is the turbine/shaft in your turbo balanced very well without its original compressor wheel? I have read that Garrett turbos are balanced as an assembly instead of individual parts like the Holset turbos. That being said, I highly doubt all of the guys with PowerStrokes running Wicked Wheels have had them balanced. I'd wager they install them and hit the road.
Travis..