Howdy and
I run shell rotella 15w40. I've run delo before. Both to me are good oils. Just as long as it is 15w40 you should be good.
It would not be a bad idea to carry a spare CPS. as for changing the one that is in there unless you are experiencing problems I would just leave it alone.
with a 4 " lift 35-36 inch tires should fit with no problem.