2001 f150 xlt 4dr 2wd 4.6.... my son bought this not running... a fuel issue..after a simple fix, it lost oil pressure after about 5 mins driving.. he coasted to a friends house and parked it.. i ebought it and replaced a plugged oil sump tube. it had a lot of noise from the pass side head and no power.. not oiling, so put on a new timing set with oil pump and cleaned out oil passages..made sure that oil is flowing to top side by leaving pass vlv cover off.. started and still has knocking as before.. its quiet at idle but clatters/knocks on acc and dec.. oil pressure is 20 -25 lbs warmed up at the sending port, no sign of metal in oil.. using a stethoscope, there is no noise on the oil pan, the tx housing, or drivers side head.. the noise is loudest at the top of the head and fairly even across... the knocking sounds like mltple rods, but the oil pressure says no..
can the lifters clatter and sound like rod noise on this motor?
is there a restrictor under the cam cap? i can not locate it
if the restrictor is missing would it cause low oil to the wrist pins?

thx