A lot of conjecture going on, until
@Mudeblue reports back on what has been tried etc, as a group we're tearing down to the block.
remember, he said there was zero oil pressure, cam bearings in the wrong spot, or block rocker shaft galley etc will still give oil pressure at the sending unit gallery, the oil goes from the pump to the front main and goes up the front of the block, there is a Y there, one gallery goes to the cam, the other goes to the passenger side Lifter Gallery, the lifter gallery goes to the rear where it goes across the back (Sending unit gallery is there) and over to the driver side lifter gallery and goes forward to the front of the block. The Rocker shaft gallerys do come from the cam branch mid way back so yeah, if something there isn't right, bearing isn't indexed, or cam oiling holes blocked you won't get anything up to the rockers, but you definitely should be getting oil pressure via the lifter gallery.
1. How long was it run without oil pressure? If it was a short stint you may have dodged a bullet, only way to tell is pop main caps, if it was less than 30 seconds go with it.
2. get an oil priming shaft and do the following before going too deep.
- spin it with a drill and see if you can feel resistance, pull the sender at the back of the block and spin it again, if you see oil you may have a galley plug out, if you don't, then start looking at the pump, it's easy to pull it and check it out and try a few things above.
But for the love of god, don't just walk away from this thread without giving a status, it kind of irritates folks that are trying to help.