hello. been a while since ive posted here mostly just been lurking around. well i have an issue with my truck that popped up recently. my old man changed the oil on the truck and a couple days later i noticed the oil pressure was quite low. the truck is an 86 with a 454 and turbo 400. the truck when you first start it up cold will go to about 30psi then once its warm it will idle at 0 maybe 5 psi. cruising with rpm around 2500-3500 the oil pressure is in the 15-20 psi range. first think i thought was maybe its the oil but he used 10w-30 like i did last time i changed the oil. then next was the oil filter he used a napa gold that i asked him to use but last time i changed the oil i used an ac delco. i thought maybe something with that i think some have a pressure release in the filter or something im not sure i just figured it was worth a shot putting an ac delco back on the same as it was before as thats all that had changed. so after changing the filter the oil pressure was still just as low. oil level is just fine as well. anyone have any thoughts? my next plan is to try a different oil pressure gauge just incase the gauge isnt working but i dont think so as it seems to still move and change with rpm. any thoughts or insight would be much appreciated.