I'm not a big fan of regular Mobil 1, but I am a big fan of their high mileage oil which I use on all my old vehicles.
It will fix most minor weeps and leaks that are prevalent on old vehicles, including the rear main seal on my old Ford Ranger. It has literally allowed me to keep vehicles that were too expensive to fix otherwise. If I keep my RAM beyond 80,000 miles, I will switch over to that.
But for now, based on overall consensus within the FCA community on Hemi, I will likely use Pennzoil Ultra Platinum for now with the Mopar filter.