Call Vortech. It's a V3, you can send it to them directly.
There is a page in their website about the upgraded impeller and data sheet but it's hard to find. I'll see if I can track down the link. Ask them about ceramic bearings while you're at it.
Just a heads up there is a third option:
Supercharger Rebuilds » Vortech V1, V2, V3, V4, V5, V7, V9, V24, V28