A newish Turbo on a C-15 6NZ blown

Yea this truck has been hidden in Houston by a coworker who's been just steadily doing local work and taking care of it for the last 10+ years. I finally bought it a few weeks ago and did this with the turbo as I opened it up a little just to feel out it's power while merging.
This turbo going out is really strange to me to be honest because it was the last thing I thought would go since it was just replaced a year and a half ago. It has me scratching my head and worrying that just replacing the turbo by itself might not actually solve the root problem and I might be right back at this point in like a month...

Thanks for the headups on how picky Peterbilt/Cat can be on accepting core turbos. I'll definitely not be buying the one on sale for $1690 until I have the old one with me because if they aren't going to accept it then I'll get a Borg

I just want to make sure I do it right so instead of just reading threads I'm here asking the pros

 

Sorry for the late update but we had crazy rain and flooding around here and I wasn't near my desktop for a bit trying to get everything situated.

The conclusion was I ended up getting the borg warner turbo that swaan recommended and upgraded the oem manifold to a pdi brand. I must say I'm quite happy with these two choices. My exhaust temp is down dramatically (hasn't even hit 900 degrees so far)

Once we looked at the turbo we found that it had blown an o-ring and that was why all the oil. The blades were a little bent but still in one piece and since I had stopped and towed the truck immediately there wasn't any oil in the intake. It was said in this particular blown turbo situation I didn't have to do the cac and coupled with the radiator shop telling me it was going to be a couple of days to get to it and the flooding and everything starting in Houston I made the judgement call to not do the cac. I still feel like this was a risk and I am wondering if I should backtrack and go and get it cleaned though..