Hi I'm new! I have a question about oil pressure and where it should run.
 

I just bought a 99 Sierra Z-71 with the 5.3 Vortec. Here is my story. I had only been driving it about 15 miles each way to work and it seemed to run great. First long trip last Sunday I thought my oil pressure seemed a little low running down the eway at just over 20 psi on the gauge. No sooner did I think that, this awful ticking sound starts and continues getting louder until I get off the exit, shut it off, restart, and bring the RPMs up resulting in a little better oil pressure and less noise. Same thing on the ride home so it was consistently happening around 25-30 mins down the eway. I changed the oil with 5w 30 yesterday and it seems to be holding a little better oil pressure. It is usually above 40 to start but as it warms up it seems to be near 30. I took it for one more good eway ride after the oil change and its again running just a little over 20 but the sound hasn't returned as of yet. Basically, at the time I'm just ruling out oil pressure issues. Assuming my gauge is reading correctly, where is normal oil pressure reading after rolling down the eway for a while? Thanks in advance!

most i see run 30-40... my 02 ran 40 (at idle) to 60 (at throttle), but on a manual gauge it was actually 26-46 or so.