It is pretty awesome, but keep in mind that this is a full tilt race engine with 13:1 compression and mechanical FI on alky using a .700+ lift roller cam.
However on another note, several racers using the 12 Port head on a race type 6 cylinder have achieved as much as a 150 HP gain over a heavily modded siamese head. So that should give you an indication of the potential available with this head design, either on a 4 cylinder or a 6.
