I thought I read in those threads that the 04 DI engine was a no go, that you had to use a 2002 or 2003 engine? If you go to the 02/03 engine you get 15 extra HP and 0 extra torque. My Axiom engine burns oil as bad or worse than my VX so what's the point? Personally I'd either go with a rebuilt VX engine or upgrade to something completely different with significant advantages, like say the Isuzu diesel for big MPG improvement or a V8 / turbo Ecotec for big HP. All depends on your budget and how loyal you are to the stock configuration.

In summary I would say "go big or go stock."