Figured I should do some preventive maintenance. So I purchased timing chain, oil pump, oil pressure sensor, and timing chain cover gasket. Since I was going that far, I figured I might as well do the intake manifold gasket, valley pan gasket, knock sensors, and obviously new oil and filter. Before starting, I had about 30-35 psi oil pressure. I bought a Melling high-volume oil pump with the pickup tube and gasket. I got everything changed, and after starting it, I have 10 psi cold. Once it's warmed up, it drops into the red and sets off the low oil pressure warning on the gauges. I figured it was a faulty oil pressure sensor, so I replaced it again. Still no pressure. So I figured it was a bad oil pump. I went and got another oil pump and replaced it. Still no oil pressure. I was very careful and made sure everything was installed properly, and I made sure the O-ring on the new pickup tube went into place without being pinched or broken. I looked to see if the oil sensor screen was installed when changing the sensor the first time (I didn't see one, and just to be sure, I stuck a pick into the hole and felt nothing).

Not sure where I went wrong or what I missed but any help would be greatly appreciated.