ok. so I just picked this up in a trade. Its a Garrett brand new rebuild. I did research and found out: in the T18A90 family, its a/r .96 on compressor and 1.32 a/r turbine. i measured and just eyeballed rough numbers since I dont have a caliper right now.

4.75in compressor 120mm
5in turbine 126mm

minor----what matters
3.75 cold=95mm
4in hot= 101mm

so 63 trim for compressor and trim = 64 turbine

Zero shaft play

I want to trade for a smaller turbo. Ball bearing if possible. within a few hundred miles of Raleigh, NC b/c I want to do a in person trade. I am thinking 76mm-80mm twin scroll. let me here what you have