Ever thought of hunting up a Royal Purple 20-820 filter to try out,as you're down a bit on pressure compared to what my 300 runs at.My truck with dual remote filters idles in the 50/51 range hot at 750 rpm,and at 65 mph runs at 59/60 psi,and 75/76 psi at it's 6600 rpm shift point. That's with 5W-30 redline and 2 big ole 30-8A Royal Purple filters.
I do have the remote SINGLE oil filter setup on my truck from Pac Brake, makes changing those filters A LOT easier.
I'll have to try out the Royal Purple filter you had mentioned.
One thing I thought however, with adding TOO much pressure, I almost wonder if that would introduce oil blowby and potentially causing an issue with the catalytic converter(s)
I've seen vehicles where here at our shop when too much oil blow by will cause havoc on catalyst system and then customers are having to replace those cats... They aren't exactly cheap.