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