360 intake manifold problem?

That plate comes off . The spiral rivets come out by tapping around under the edge with a small chisel. They spin while coming out like a screw. Clean under it , straighten it and reinstall by tapping them back in. If you block of the exhaust cross over in the intake it is not needed. It is there to keep the oil of the hot exhaust cross over that is used to heat the intake and also operate the choke