drop in oil pressure

Yes. And so will everything else that is lubricated. If you're just have a light/ gage showing low oil pressure showing low oil pressure try replacing the oil pressure sensor. Oil pumps are usually bullet proof.

if there is a drop in oil pressure then you someonething wrong with your crankshaft. if one is not doing its job that will make you lose oil pressure. take of the breather on you car/truck/suv and rev it up pretty high, then let idle. crawl under and listen for the noise and use your hand to feel vibration, note wear pair of gloves