Inliners International Forums General Discussion Engines 250, should I switch to a 292 exhaust manifold?

As for the gasket remark, use a rimflex gasket.

The big issue for some of the headers is warping of the flange. I have run the same set of Clifford headers since 83 or so. They warped within the first two years. Built up the sealing surface on the face of the header flange with weld, and ground it flat and parallel. Rimflex gasket, no leaks, if you decide to bite the bullet and get a set of tube headers.