I'm currently rebuilding a series 5 turbo engine to swap into my Gtus. I bought the engine from a guy who said it had no compression on the rear rotor. I pulled the engine apart last weekend and began cleaning the housings, irons and rotors and found something somewhat concerning with the rear housing. There is a small gouge on the bottom edge of the housing, and I'm not sure if it's something that can be re used or will need to be repaired or replaced. The gouge is big enough to feel with your finger nail. Attached are some pics, what does everyone else think?
Thanks

 

Replace it. If you send then for resurfacing job, it might be to much material they have to remove.
Sorry..