Abstract: An exhaust manifold, cylinder head, or the like, is provided with one or more insulating shield members formed within associated housing members having ball or cylindrical end portions. The end portions are seated on bearing rings preferably cast or inserted into the housing ends to provide for relative expansion of the internal shields with respect to the outer housing members, both linear and bending expansion motions being accommodated. The resulting passage assemblies may be formed by casting the housing members around their respective shields. Sand core material may be preapplied to create the desired insulating clearance between the associated members and, if desired, to secure the bearing rings in position.