I bet your answer will be 4000 mHz 19-19-19-39 there, and tighten timings... But please listen
I just upgraded my PC 1.5 months ago (from 10 yo rig), and currently use LPX Vengeance 3200 16-18-18-36 because it was cheap and guaranteed stable with my system, without notch.
But... i am feeling...