This page gives a pretty good overview of the specs and construction tecniques of the new GM inline engines.
http://www.castsolutions.com/pdf/Engine_2004.pdf As I mentioned before, there are a number of people making very good numbers using the 3.5 with t3/t4 hybrid turbos or t4's. As you can see from that site, the casting tecnique allows them to produce a very high quality package.
