You can get them from D&D Performance too.
You can reach them at (248) 926-6220 or on the web at
www.ddperformance.com
They have a speedo gear chart there too!
What's interesting is that they comment on the white 23T gears stating that they are not a Ford gear and therefor don't mesh perfectly with the tranny drive gear. Thus, they can become stripped - which is exactly what happened to me with my old T-5 setup.
Hope this helps,
E