98 k1500, 5.7 liter engine. Got the truck a few days ago. I have the receipts for all the parts bought and put onto the truck from the previous owner. Pretty much the overhead of the engine was gone through and everything that was bad was replaced including the lifters and pushrods, o2 sensor, spark plugs, wires, dist cap & rotor, fuel filter, brake booster, injectors cleaned, and new upper intake manifold gasket, and new throttle body gasket. Also has new alternator and battery. It's straight piped true duals with no cats.

The truck has an oil leak and the previous owner said it was probably from the oil pan or rear main but he didn't check it out and neither did I yet.

Anyways I started it up earlier today. The oil pressure was at about 60 until it warmed up and then it dropped to almost 0 at an idle and the check gauges light came on. When I revved the engine, the oil gauge increased to around 20 or so, maybe a bit more. Once the RPM decreased and it fell to an idle, it dropped back to near 0 and check gauges light came on.

After about 3 hours, I checked the dipstick and the oil level wasn't on the add mark, but rather up above it a bit - it didn't look all that low. Should I try adding more oil or try measuring the oil on a hot engine instead to get a accurate reading? The body has 295k and the previous owner said he was told the engine and tranny weren't the original. I'm just hoping it's not worn bearings