This is a very serious streeter, and with the power to weight ratio, is like driving a race cart.
It is a pity, that Holden stopped making this type of Inlet system.
No other car manufacturer has produced a manifold like this, and combining this with the std factory cylinder heads that flow over 400hp out of the box, it has a very unfair advantage over rival Fords and even Chevvy's.
As a comparison, this combo made 407hp at the tyres, whereas a 300kw HSV GTS GEN 3 makes 356hp on the same dyno, and HSV 250kw GEN 3 made 290hp.
On the same dyno, I saw a new TE50 5.7L Ford Tickford with new custom exhaust make only 223hp at tyres.
I felt sorry for the owner, altho' the car was very new, and also the Ford had more low end torque.