I run Rotella in most of my vehicles but I heard that there had been some recent changes to the formulation that may remove any benefit that might have previously existed for older gas engines, probably what 72C20 is referring to. You could throw in some additives but at the end of the day might be better to just switch oil.
I just bought some of the below for my new crate motor.
https://www.summitracing.com/parts/j...EaAhEvEALw_wcB