Hopefully the 6.0 has been bulletproofed or your nightmare is gonna continue.
They only need bulletproofed if they have had a tuner on them, or have been dogged hard. This one doesn't show any of that. I have checked everything before I bought it. The deltas are within 8° of each other, the HPOP is really good, turbo operates as it should, vanes open and close properly, etc. It never had a brake controller mounted in it, so mounting mine took some effort getting the factory harness out of the stock location up under the dash.
6.0's get alot of criticism, they aren't as bad as people think they are. There are MANY of them on the road without having any issue, as long as you do proper maintenance they will take care of you. But yes, if you don't do the due diligence of checking them and making sure everything is as it should be they will cause you all.sorts of trouble.