If you've never pulled the EGR valve, it might be a good idea, so you can set a baseline. With your miles/hourmeter of 38, I'll bet your EGR is in decent shape if you've been running ULSD, but it would'nt hurt to take a look. If it is wet in there you may have a leaking EGR cooler, and you will be able to see the moisture. If it is just a little oily soot, clean her off (don't get any cleaner in the EGR body hole), but a new O ring on and away you go.
If you can pull at least 22 pounds of boost at 3300 RPM (find a hill, or tow a trailer - it's supposed to be a loaded test) then all is well with the turbo itself. If during normal cruising, you find that the truck surges, you may have a VGT solenoid that needs replacing or cleaning of the turbo, but that is more rare.
