31 essex carb/ exhaust

hzin711

could anyone explain to me what the block off plate on the exhaust manifold I said for. When I bought the manifold it came with block off plate and another plate. One of them connects to the carburetor which I believe gen in my car wouldn't work. I have both pieces and have been using the block off plate because I was unsure of how it connected to carburetor. Should I have it connected? Does anyone have a picture of the way their car is set up. Here are a few pictures of mine 

thank you 

bones1931

1930 Essex Engine connected.