I'm assuming you are meaning the GT38R. If that's the case, I am running it with just a tune, intake, exhaust. Nothing major done. I bought it in preparation for injectors and other mods, but that being said, it works just fine now. Mine does spool a bit slower, but I also swapped out the 1.0 A/R turbine housing that comes on it for a 1.15 A/R housing. It does have a "unique" sound that is louder than most turbos, but works like a champ.
I would say without studs on a 7.3 and just tunes you are fine. Stock tranny.....I wouldn't trust that with JUST the tuner.