FFguy808 wrote:I have seen the dual throttle body for the VVT-I 1MZFE on ES300, i wonder if those fit...looks cool

if you could source one of these dual throttle body setups (almost all 2001 siennas had them), they would bolt up to your existing intake manifold, all you would need to do is replace the drive by wire system with the throttle linkage setup from the other car. I HATE drive by wire.. There is a delay with drive by wire (electronic) system becuase when you press the gas pedal, it is picked up by a sensor, then it goes through the ecu, and out to an electric motor, which then open or closes the throttle plate. With the older mechanical linkages, thottle response is faster, meaning: no delay! Not sure if you would retain cruise control though. Might have to check into that. But having dual throttle bodies would be awesome!. You could run dual cold air intakes on each side of the bumper.
EDIT: BTW our cars are drive by wire