exhaust leak choke stove

I have the exhaust manifold where the choke stove is open to the exhaust gases and it's leaking where the choke thermostat attaches. Has anyone had any luck sealing it with high temp silicone? Any other options? I don't have any spare remeflex to use.

I do have a later exhaust manifold that has a sealed choke stove but i will be putting that on later when i am ready to install the 2 barrel intake.