I bought a set of Big Block exhaust manifolds (70-71 383/440 HP) that has a fully intact passenger side heat riser assembly. Everything is there and turns freely. My question is about how it should operate. It would seem like the plate should be closed when the engine and manifold is cold, and when the car is started and everything gets heated up, the plate should open.

Everything looks to be in the proper places, but the plate is fully open when the manifold is cold, which seems backwards to me. Does anyone have any expertise with this setup?