I don't think the cast iron HP manifolds have a different exhaust opening than a standard low performance manifold, so I would guess that any A-Body exhaust manifold used on an R/T, EQ or similar head would have this issue. I know there are two LA exhaust gaskets, the pressed metal one and the fiber one, but I don't know if the opening is different between the two. Regardless, I am pretty certain that no matter what manifold is used, if the fiber gasket is used with it, there will be a leak at some point in time.
