[Rick Parker]

Just a thought, be sure that either the manifold or the thermostat housing has a machined recess for the thermostat to register into, one of them must have this. Put a light coat of gasket sealer on the suface of the part that has the recess, install the themostat, the gasket and let it set up for a few minutes, THEN install the neck & tank assembly onto the engine. Be careful that the thermostat does not become disloged and fall down while attaching the neck. This assumes the surfaces are flat as mentioned previously. 12-15 lb torque is plenty. All the Windsor manifolds I have seen have blind holes for attaching the neck and do not require sealant on the threads.