I daily my ‘64 Dart (225 Slant 6) and usually have no issue. The past few weeks i had a low oil pressure light on, but had plenty of oil so I changed my oil a week or so ago. I should note, after looking through service records, my mechanic most recently put 15W-40 during an oil change, whereas I use the recommended 10W-30, so I had mixed oil weights when topping off after checking fluids previously. Well after the oil change, light stayed on. I haven’t driven much this week, last time I drove was Sunday. Today when I started my car, the engine didn’t so sound right, slightly bogged down, and when revved (in neutral), squeaked. I revved again and it’s squeaked again. I have enough oil according to the dipstick. I suspect there’s an issue with the oil pump and the engine is running dry. Any thoughts?