My oil pressure is going away.....

Idle is not a good measure for oil pump output. What pressure is it showing at 2K? Even for a HV oil pump, 25 PSI is fairly high oil pressure at idle. Remember, all an engine really needs is 10 PSI for every one thousand RPM, so oil presure can be in the single digits at idle and all is well. I wouldn't worry unless the pressure has changed from the onset. Has the pressure dropped when the engine is hot as compared to when it was first built? Even a little drop is ok as the bearings are breaking in and getting seated to the cam and crank and the oil pump rotors are wearing together. It's perfectly normal for an engine to have higher PSI when cold and then drop pretty significantly when hot. Also, hot weather can have an effect as well. I don't know about the noise, but I wouldn't jump the gun on the engine yet. Mopars are a pretty easy engine to get right and they rarely ever give problems when assembled correctly. At 4K miles, I'd have to say if something was wrong, it would have happened long ago. If you're really worried, drop the oil out of it and check it for metal shavings.