The Stovebolt Site Forums The Shop Area Engine Shop Too much driveshaft gap and what is this?

In the second picture I believe you are asking about the exhaust manifold heat riser? When the engine is cold, it will direct the warm exhaust up to warm up the carburetor. When the engine warms up, the heat riser will rotate and direct the exhaust down through the exhaust pipe. There should be a heat sensitive spring on the other side of the exhaust manifold.

Or, are you talking about the Bell Crank Mounting Stud? This is where the carb linkage connects from the gas pedal to carb.