Originally Posted by NitrousZ34

Those two intakes go into a throttle body on each side, just like the manifold on the right. You can't have two intakes going into a single throttle body its just not possible. The manifold on the left is from a DE 350z from years 03-06 and the one on the right is from a HR 350z years 07-09 which all had dual throttle bodies.