L31MaxExpress
I'm Awesome
Take it from a guy who used to work at a BMW shop. You don't want that in your truck. If you did go inline 6, and I personally think you'd get originality points at least, go with the Toyota 2JZ, a far superior and proven power making platform.
Nissan TB48 would be my choice....1000+ HP Turbo Patrols.
Then again the prototype Trailblazer SS had a twin turbo Atlas 4.2 I6.