Use 0w20 year-round. I've used M1 0w20 AFE exclusively in my Ram for several years- no loss of oil pressure even when towing a trailer in >100F ambient. 0w20 oils are made from some of the best base stocks out there, I generally prefer them to 5w20 oils.
Valve train changes, different lash adjusters and updated rocker arms. Also dont, forget an egr valve was added in their somewhere.
But those changes would not have anything to do with oil grade, or would they?
I have 2 of these motors and run 5w-20. but alot of people run 0w-20 without problems.