Slight rattle from engine when revving up (SBC 305)

[sethv]

Hey guys. Recently I had 0 PSI oil pressure on idle, so I revved it a little bit to see if the pressure would go up (And it did) and then it sounded like a slight bottom end wrap around 1800 rpm or so (Just in park...) Changed the oil and there are zero metal shavings and the oil was smooth. Had a JUNK Fram filter on it and replaced it with an ACDelco one. Cold PSI went from 15 with the Fram to a little more than 30 with the ACDelco. Still has that slight wrap but it's not down on power and the oil level is fine. I can't hear anything under acceleration, it's just doing it from idling in park or neutral. And it's holding pressure now. I'm not sure what the problem could be, since the last time I had a bottom end noise with my 350, there were metal shavings everywhere. This 305 is clean and only has 60k on it. Can't take a video right now though. What do you guys think it could be?