valve chatter 360 magnum
That’s because the factory didn’t send it out with loose clearances.
I’m not sure why so many are struggling with using a higher grade oil to get the pressure up.
If I ran 20w50 in my engine it would over ride the bypass and blow the filter off.
If the OP tried to run what I use (0w20) he might never see 30 psi where I will see 90 or a skosh more on cold start and I’m figuring a hot idle of 45 psi at 1k rpm.
I’m not against using thicker oil,,,,,,the roller lifters don’t agree with it though .
The internal clearances in the lifters don’t like it .
My son used 10W40 for many maintenance free miles in his,,,,but never 20W50 .
If the pressure is truly that low,,,,there is an internal clearance issue somewhere in that engine .
Sounds like it has good power,,,,,just not good pressure .
Tommy