This came as a pretty good shock to me, but it seems as though the truck runs like a raped ape and really idles a lot smoother.

60k on the clock, and just switched from conventional Rotella to Synthetic 5w-40.

Normal? Or am I just imagining things?

I think you're imagining things. It may run a tad smoother, but there's no way you'll feel a power difference, unless a predator or something slipped in with that oil change! Though you can rest easy knowing your motor has synthetic in it! :D

I did bump up the Predator from 65 to 85....but that 85 tune almost always makes my idle unbearably lopey and unsteady. Oh well.

Glad I switched tho!