I have this center cartridge that is supposedly a Garrett. I bought it as a S4 hybrid turbo which turned out to be damaged. So I'm rebuilding it and looking into making it better. I'm really wondering if i can convert it to ball bearing.
There's no stamping or ID plate on it either. But it does bolt up just fine to stock FC turbos. I have a Air Research To4B compressor on it.
Here's a few pics of it.
