Need more power

[Roadkill]

So I bought a 2011 Yukon XL 2500 in July, and while I love my XL, I want a little more power, and hopefully if my foot isn't all the way into it, a little more fuel economy.
So I have the 6.0l, just wondering what I should do first. Tune, CAI/Spacer, or exhaust?

 

[ezdaar]

all 3 minus the spacer.
If more, cam and a converter.

Not going into specifics as there's a million posts here about this very subject.

 

[Roadkill]

Thanks buy I was asking specifically for the 6.0l. Web search doesn't pull up too much for the 6.0, so I was wondering who has modded a late model.

 

[felixgun]

CAI then Tune. Exhaust supposedly helps but when I did my BB Tune, Justin said it doesn't really affect the tune.