If ya want to keep the noise down and still have good power. Go with some Flow masters.
The 6.2 will rap real hard and loud with straight pipes.
The Flow masters used on a larger cube mouse motor will sound real nice on your little diesel.
In fact, other than the rattle under the hood, the exhaust note is very similar to a small block.
Adding some larger pipes and the flow masters will really help things. 2-1/2 pipes from the engine to the mufflers and maybe 3 inch out the back.
This will give you about all that the little 6.2 can breathe anyway, plus sound nice and not drone in the cab.
As mentioned, a turbo engine is a lot quieter even with a straight pipe than an NA engine.
The exhaust note gets muffled a lot after traveling through the turbine wheel.
Have fun and keep us posted.
OH BTW, resist the urge to use glass packs, they really sound horrible on the 6.2
Missy