Turbo failing or actuator failing? Rare for the turbo to fail.
Really not worth going to a "bigger" turbo unless you can get the tuning/fueling to compliment it.
Also what are you goals? You could end up with something that has higher peak HP but is going to be a dog down low.
Lots to consider
This is my first post and probably my last considering the amount of 'Google Mechanics' I am seeing herein and the likelihood of being banned I put at 99.999% LOL.
Your post irritated me so badly that I registered just so I could reply to it.
You said "Turbo failing or actuator failing? Rare for a turbo to fail."
Rare you say?
WRONG, INCORRECT, FALSE, NOT TRUE Pick one.
If you are running a stock Ram Cummins Turbo diesel, Turbo's (especially Gen. 3+) are infamous for failing at 45,000 miles (+/- a few thousand miles).
You are CLEARLY responding to $hit you are CLEARLY ignorant of. Do you even have experience as a mechanic, technician or have even done your due diligence and researched for the OP before spewing that bs out of your mouth?
Bottom line, it is NOT rare whatsoever. The turbo WILL fail eventually without making aggressive changes to the system as a whole IOT prevent that. This is why I deleted by '14 at the 32k mile mark, to save my turbo. Had I let it keep going like that with all of that DEF particulate inside of the turbo, it would eventually warped it / gummed it up, and the turbo would have had a catastrophic failure.
People are using stock drivelines dragging their tucks at over 800hp. Can you add some upgrades when electing for more power? Yes, it doesn't start at the driveline. You DO NOT know what you are talking about at all. There are much more important upgrades to consider when going above 600 ponies and it DOES NOT start with the driveline ffs. Same goes for you