Morning,
The polymer AFE Torque Tube pricing is the same as the metal one, better part for flow etc and looks better too, in my opinion anyway. The tube will work with Stage I intake system or the stock air box (haven't done this but have been told it works fine). Totally smooth mandrel bends and no inner parts to keep the hose from sucking down problems that impede flow that some parts have etc. The Stage II does come with an intake to turbo tube but it is totally different than the Torque Tube. It's got a 5 inch inlet for the filter, which is mauch larger too, bolts to the air box and is shaped a lot differently and reduces to the size of the turbo inlet at the turbo. It's a much better flowing intake system, but as always it's a lot more money too. Call us if you have any questions etc.
Mark @ DPPI