hey guys my dad has a 6.7 we have done the dpf delete put a bigger intercooler , true flow stage 2 air intake and added an mp-8 he wants to upgrade the turbo yall have any ideas what would work well with this setup

 

Well, an aftermarket CAC is probably one of the last things to upgrade n a common rail - the OEM piece is very good.

The HE351VE is a great turbo, it just needs to be unchained.
With the ability to make power through 50psi (albeit with the penalty of expansion boost) and a large exhaust housing which restricts down to less than 10cm, it's the best factory turbo yet.

Instead of a pressure box, I recommend reprogramming the ECM with an S67 (ME version is what we use).