Isx15 2250 turbo squeal

[JasonD5746]

Yea, it's the gasket. One rear nut was missing, other was finger tight. One front nut was tight, other looks like it was replaced with a bolt which somehow was bent. Had to use universal wrench to get it off. Anyways, metal gasket was blown to the rear(backside next to engine). I have a few specs of aluminium powder on impeller. This thing has 575,000 on it. Go ahead and replace turbo while it's off or run it..?