Well I cleared myself up earlier. I meant 400 to the crank, not to the wheel.
People are hitting 340-350 whp (if drivetrain loss is %15 it's about 391-403 to the crank) with just I/H/E and a tune. Stock intake manifold, stock throttle bodies, a few other stock things that
MIGHT bump the power to 400 CRANK hp
or get very close. At least I would think so.
It comes with 336 hp and the intakes and exhausts on the 370 are extremely restricted. This VQ is different from all of the other ones. It's bigger. Comes with a bottom end that, according to paper, lol, can handle 1000whp. Has a different type of valve control unlike what I've ever seen in a vehicle.
But here's the specifics on the motor and where that 1000whp claim came from.
http://www.370 z.com/MagazineArticles/tabid/57/articleType/ArticleView/articleId/14/370Z-Engine-VQ37VHR.aspx (take out the space after "370")