my 351w isnt getting oil up to the valves apparently, although my oil pressure is fine as checked off the sending unit. when i take off the filler cap with the engine running, not only do i not see any sign of oil circulation-- not even any push of air out of the filler hole. oil level is fine, pressure as i said reads fine (i removed the sensor to check it mechanically), i have a minimal drip leak from the front seal, but it is literally a couple drops a day. I'm obviously not driving the thing but i'm confused... why would the pump, as it seems to be functional, not move oil throughout the engine? i've got no oil in my coolant, no apparent cracks, etc. is it time for a rebuild? what could be causing this? i'm going nuts! thanks.