You worried about those ITBs being too big? 12x 42mm is a lot of throttle body for a 400hp engine! Think you need some bigger cams for this beast
Not worried at all they are the exact same size as the stock intake runners. These ITBs are used on a lot of other cars with around 2L 4 cyl engines, this is basically that x3. https://www.youtube.com/watch?v=3pzuEyn4WgI That one even made 450hp with 50mm diameter BMW M3 itbs.