Guys, I have been meaning to ask this since I got my turbo rebuilt. I bought a "15g" wheel to replace what I had that was iffy. I had previously lathed out the bearing housing to accommodate a 58mm 19t wheel. Was I wrong in thinking that the T was a larger diameter wheel? I know the 15g is SUPPOSED to be 56mm but Mine is 58 and it has the varying blade heights. I'm confused about this now. I know the wheel fits the 15g housing like it's supposed to but I measured the outside at 58mm with a digital caliper.

 

I think you might have better luck asking this over on Volvospeed. They spend their time discussing performance modifications more than just repairs like "we" do.