Greetings to all, Here's the story: I bought two damaged K04-023s for less than 50£, hoping i will end up with a good turbo after a rebuilding process. I broke the turbos apart and here's what i found: One of the compressors have been apparently upgraded in the past as it have a bigger wheel with 12 blades that won't fit in the other compressor housing: Compressor hosings side by side (the left one is stock while the right one is upgraded). Notice that both of them have been "scratched" by the wheel Back plates also damaged The upgraded compressor housing is out of discussion as i have no idea what wheel have been fitted in the past and i don't want to risk buying the wrong one. So we're left with the stock one. As the shaft have also been damaged, i was thinking buying a new CHRA and fit the housings. My question is, is this compressor any good to use? My concern is that the gap between the housing and the new wheel will be bigger, due to the housing wear so it won't boost right. Anyone experienced this kind of problem, or knows enough about turbos to put some light here, please do! Closer look on the stock housing: Should be mentioned that the wear is only on that round surface. On the inlet side where the top of the wheel is, apparently there are only minor scratches. Any help would be appreciated!