lost all oil pressure but not flow

hey everyone, just want to start out that i appreciate all the help on this site everyone is always super helpful and i greatly appreciate all the help i receive here on FABO anyways on to my question

car is 72 duster, 440 source stroker, 505 c.i. melling high volume oil pump purchased from 440 source, 7 inch deep pan, windage tray stud girdle, joe gibbs high zinc 5w30 oil etc... anyways motor has been running since last fall when cold motor consistently had 70-75 lbs of oil pressure at idle,even in below freezing temps, once water got up to 180f oil generally went down to 15-20lbs but with any throttle application would spike back to over 60-65 lbs. all was good...

well engine has probably about 5 hours of run time on it at this point, this spring i pulled it to fix leaks around the pan rail, timing chain cover and water leaks out of the freeze plugs. reinstalled around a month ago, no leaks

probably put another 3 hours of runtime on it since cruising around the neighborhood fixing other issues that have came up all while no oil pressure issues, well this weekend buddy came over and i needed to get gas so we decided to take it on the approx 3 mile trip to the gas station, we make several 6k rpm pulls on the way no issues, leave the gas station, still rock steady pressure, we head back, make another pull to just before 6k and cruise into the neighborhood off the two lane highway, about 2 blocks from home check oil pressure, its at ZERO, lightly rev it, to see if i have anything and nothing, shut it off and buddy flat tows me back water temp never got above 190 according to aftermarket temp gauge

we check oil level, all good, pull oil line off block start it buddy says its spraying out like crazy okay cool, either have a bad line or gauge, that was saturday skip forward to today and i buy a new line after work install, start it up no pressure, shut it off, pull new line from gauge and put line in water bottle, start it and no oil goes into bottle, disconnect line from block reach in turn key look at block and oil is coming out but my buddy may have been exaggerating a tad, oil is lightly pouring out of block, not quite gushing and spraying like he said....

anyways a lot said there but i wanted to describe problem as accurately as possible to everyone, at this point really dont want to start it anymore than i have to as i feel like i am already pushing my luck seeing it may actually be a pressure problem and not a gauge problem as we anticipated... so any suggestions? im thinking maybe a clogged filter? it is on its third one since initial build but only 1st one since resealing bottom end and freeze plugs, or possibly a broken spring in the oil pump? want to reiterate i have zero oil pressure at any rpm and not one drop came out of new line even with a light rev, other than that motor does not show any signs of anything wrong, just want some tips on where to go from here, as worst case scenario i can think of is possible cam bearing spun or something of that nature anyways any tips would be appreciated just dont want to chance locking motor up changing things will not make difference and testing

thanks FABO!!!