1936 Exhaust manifold sealer

[Burgie]

Has anyone had success using high temp silicon sealer on flathead exhaust manifolds? A friend suggested Peratex Ultra Black.

 

[Kube]

Has anyone had success using high temp silicon sealer on flathead exhaust manifolds? A friend suggested Peratex Ultra Black.

I'm guessing you are referring to the area between the manifold and the block, IE the gasket. Yes?

If so, there are special sealers for exhaust systems. Permatex silicone is NOT one of them.

Occasionally the need for two gaskets sandwiched together with sealer does the trick rather well.

 

[GB SISSON]

I would suggest you look into Remflex compressible manifold gaskets. I have bought multiple sets for flathead V8. They are good for a couple thousand degrees and squish to fill gaps in such things as warped headers. My local Napa store can usually get them the next day for most applications.