The passageway includes {HEAD ~ a fuel delivery end} located in {TAIL ~ a firebox} and a fuel infeed end below the plate 
located in
The passageway includes { HEAD ~ a fuel delivery end } located in { TAIL ~ a firebox } and a fuel infeed end below the plate
OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH