Because he'd be AFCing them, tuning them way down when it came to power. I think the Nismo 740's ( there new ), which requires you to have 95 manifold ( junkyard or ask dude down in GA ( Russell ) that worked on his car ) for that part. Since the upper manifold comes off anyway, and he may be looking to replace fuel rail etc. Sitting right on the border of high horsepower and highstreet power. Either way tuning is going to be needed ( as we know ).