Numerals 421, 451 and 461 represent solenoids of {HEAD ~ the change} over {TAIL ~ valves} 42, 45 and 46 
Numerals 421 , 451 and 461 represent solenoids of { HEAD ~ the change } over { TAIL ~ valves } 42 , 45 and 46
OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH