So I have 3.8l 231 V6 non turbo 87 regal, the engine has 187k+ on it. For engine oil pressure at 1600-2000 rpm’s it’s at around 20 psi on cruise. Idle is about 12 at 1000 rpms. But at stop lights when I’m in gear the pressure drops below 10 psi. I did the timing chain cover, I replaced the oil pump and the timing chain cover completely as it was a suspected leak, when primmed I verified oil coming from every rocker so I know it’s not a priming issue. I’ve had 2 mechanical oil pressure gauges in the car to make sure it’s correct. My final thoughts are to do the main bearings which i don’t think anyone wants to do. Any advice would be appreciated.