Here is a UAO (Used Oil Analysis) of your oil, there is no Moly (Molybdenum). Guy, I have never even heard of a high end oil without moly, that is horrible. Your oil had a lot of detergents but lacks friction modifiers like Moly. Moly is exactly what the hemi tick needs or visa versa. Read the synthetic thread and make a choice on a better oil. be careful with moly additives, they are not the same as the Moly used in high end oils. There are different types of moly.
At 42k miles on your truck it is probably time to replace pcv, that will als0 help oil rotate through your engine better if it is getting jinked up. When a pcv is gunked, oil sludge starts forming, often all you need to do it replace it and the oil system cleans the sludge out automatically.
I looked up a virgin oil analysis on castrol syntec just to verify, and again no Moly. Detergents like calcium help the oil run clean, but Moly content helps reduce friction on metal parts like lifters. I would bet 5 bucks of my hard earned money( I'm Retired

), if you switch to Redline that tick disappears. Redline has more Moly then any oil I've seen an analysis on. I would even try Running Royal Purple as a backup if you don't feel like ordering the online highend oils.
I just looked it up, Royal Purple has twice the Moly as Amsoil (i was pleasantly surprised at this), not close to as much as Redline. A very good choice to see if it helps that tick, on the off chance it is the Hemi Tick.
Castrol Syntec 0 Moly
Amsoil in the 85 range moly
Royal Purple 175 range moly
Redline 800 range moly
The very fact that your oil has no Moly leads me to believe it is very possible that is the Hemi tick.