The newer engines are designed to run with the thinner oils....and the mechanical gauge is probably a bit more accurate than the factory "gauge" ever was.
thats normal oil perssure for how chrysler is building motors these days, my 6.1 uses 0w-40 and at an idle of 750rpm it has 28 PSI oil perssure with an oil temp of 229F and at 70MPH/ 2250 rpm with an oil temp of 229F oil perssure is 62 PSI.