Novi2000 extremely loud after rebuild

[96dreamer]

Little backstory. I bought a used novi200 mostly complete kit that was supposed to have been rebuilt a few years ago and just got around to installing and running it this year. After less than 100 miles the impeller nut came loose and destroyed the impeller and volute. I bought another used headunit and went through it myself this time. All new bearings and seals. Bearings are correct and I do not see any damage or issues with either gear set. I got the new rebuilt headunit installed this weekend and the thing freaking screamed. Significantly louder than the old one the ate itself. It was hard to even hold a conversation next to the car while idling. I disassembled it after idling and there are no signs of issues. Bearings seem ok no signs of wear, impeller looks good so I'm a little stumped. Before sending this one out and losing another couple hundred on a rebuild I thought I would see if anyone had any ideas.