Contact Dave and ask him about what he does. He has a method of using telfon sheet for a bushing that will never leaks, wear out or bind. Though he doesn't do it, he will just share the how to. http://www.davessmallbodyheis.com/
tin indian performance has one available on their website http://www.tinindianperformance.com/Qjet%20carburetor%20replacement%20parts%20and%20services.htm. Ive used it and it works fine. I think Gessler has one on his site too, definitely has the bushings. Cliff ruggles site - http://www.cliffshighperformance.com/bushings.html, all state might sell one if you call- http://www.allcarbs.com/shop.html Ive seen some from shops on ebay too. shop around there are a lot of them out there and they all cost a little bit.
Dave may not advertise it, but he can tune a carb with the best of them. Below is another site that walks you thru the entire process. They also sell the bushing kit. I suspect Summit, Jegs, etc. also carry it. http://www.quadrajetcarburetors.com/bushingkitinstructions.html
