{HEAD ~ A benefit} to {TAIL ~ the use} of either manifold 401 or 401′ is an increase in allowed tolerances during assembly of the unit 
{ HEAD ~ A benefit } to { TAIL ~ the use } of either manifold 401 or 401′ is an increase in allowed tolerances during assembly of the unit
HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH