If you want to find one you can rebuild yourself and run, find one of the 6000 series, ie the first number is a 6, the other 3 are anything else. The 9000 series are the smogger carbs, which would need some rejetting and other mods before being good to use.

The Vaanth Thermoquad Guide has all the numbers you need to see:

http://members.shaw.ca/crussel/thermoquad/tqguide.html