Anything is possible. Budget is the big question. Figure 10-15k$$ just to build a bullet proof tranny and the internal engine work needed and I think thats on the conservative side. I would definitely start from the tranny up though. I don't know what the differentials can handle power wise before you start breaking things. Thats a lot of power for an AWD. SOunds like fun! Go for it!
Whats 400awhp like 550-600 at the crank?
Here is a good thread on engine internals:
450whp from ej20 what parts should I get?