Low Oil Pressure after numerous replacement parts

[RichLo]

I dont blame you, still run a mechanical oil pressure guage first though, it would suck to sell a truck because of a faulty guage or sender unit.

 

[Mike Duckworth]

I had a problem with my 1990 Silverado oil pressure going high and low and the wire bundle running on the engine side fell down on the exhaust manifold due to the plastic strap holder breaking from heat. The oil transmitter wire was on the bottom of the bundle. The gauge would work good until the motor warmed up and I hit a bump the wire would make contact with the manifold. If you have hydraulic lifters, you have some oil pressure, or the lifters would not pump up. Just my 2 cents worth.

 

[Chase]

Yeah it has pressure and doesn't make any sounds or indications that it's lost any per se, its just annoying to see when driving since it only drops once i come to a complete stop after its warmed up.

I had a problem with my 1990 Silverado oil pressure going high and low and the wire bundle running on the engine side fell down on the exhaust manifold due to the plastic strap holder breaking from heat. The oil transmitter wire was on the bottom of the bundle. The gauge would work good until the motor warmed up and I hit a bump the wire would make contact with the manifold. If you have hydraulic lifters, you have some oil pressure, or the lifters would not pump up. Just my 2 cents worth.

 

[mistaake]

I kinda skimmed the thread but have you confirmed with a mechanical oil pressure gauge?