Strange Manifold noise after 10,000 miles on a new truck.

It's very hard to say without hearing the truck run ourselves. If you believe it is not a normal sound take it back to the dealer service so they can diagnose it. It a brand new truck what could possibly be wrong. All the best riding in the orange pumpkin to you.

 

What's with your exhaust stacks opposite of each other?

 

...like emailing a dentist about toothache...

 

With that RHS stack turned that way, it allows airflow down into the stack while driving and could be trying to force your turbo to spin backwards.
That’s why a wrecker driver puts caps or jugs over the stack to keep that from happening, has been known to mess up turbos, but that’s when the engine isn’t running and shoving air down its throat.

Id start by turning the stack, the whistling could be the turbo

 

Yep. Turn the stand pipe around before you loose the turbo. That is what the gauge is trying to tell you.
I’ve seen a handful of new 389’s going down the highway with the right hand pipe rotated like that. I wonder if they are vibrating loose due to bad clamps or not tightened correctly. I hope the dealer didn’t do that on purpose.

I thought it was a new trend at first. Lol!

 

A lot of these new trucks only use one stack even if they have two. I don’t know which one they use.
@pushbroom @Goodysnap