Exhaust manifold question

Hello good community.

This time I have a problem concering my exhaust manifold on the passenger side on my Olds 350 engine.

On the flange of the manifold - the one that connects to the pipe heading back and out - I seem to have one "extra" cast iron flange thingy. I can't seem to locate this in my service manual when studying the exhaust system, and I most certainly have a leak from there.

Here, pictures speak better etc:

Looking down from top. It is connected to the manifold with one stud that doesn't seem to be removable, hence it's swiveled out of alignment in this picture:



From the underside of the car. Here the stud is more visible:





It's not showing up in the manual, and I'm fairly certain the leak comes from the flat part where the manifold meets this extra thing.

Is it supposed to be there? Do I use two doughnut gaskets here - one on top and one on bottom? No idea if the manifolds are original. Old diesel car, converted to a gasoline engine. Manifolds might be from diesel car. It's a crossover system.

Thanks in advance.

Blue Knight said:

That's a ..... ?? Its was used to keep heat in the motor during start ups/ warm ups. Yours looks like to be disconnected /modified for better exhaust flow. And yes there's a flat gasket that's supposed to be there.

Click to expand...

Ah, thank you. So in other words, it's not needed and can be removed? Don't know if I'm able to be because of that stud though.

Blue Knight said:

No you don't "need" it but the only way to get rid of it is to run headers. I've never seen a half doughnut gasket.

Click to expand...

Half a doughnut? The gasket seems to fit the manifold perfect when I turn it out of the way.

EDIT: Better pictures. Just removed the manifold from the car.

In place:


Swiveled out:

Yeah, headers would be nice. Any suggestions? Easiest job fit, and affordable for a Cutlass wagon?