Wow, thats a great idea! I forgot about that engine entirely--which is what everyone else does too. Its actually built VERY well and is like the 1UZ in that its overlooked like crazy as well as overbuilt. I believe GM/GM Performance built a twin turbo one-off "just for kicks" a while back and got an easy 400 HP out of it, if not more.
Oh, and it looks
nothing like a BMW engine btw
BMW engines are tilted 15* towards the exhaust/passenger side, their VANOS looks very different, etc.
Take lots of pictures and document and post all progress. I'm very curious to see how this comes out.