As several posts suggested, try Holley. I just had them rebuild a set of carbs from a 1962 Ford 406. They did a fantastic job, including replacing the butterfly shafts, ultra sonic cleaning, rebuilding the internals, new floats, gaskets, and exterior paint. Cost, including shipping was a tad over $600 for three carbs. What I am trying to say is that their customer support has improved drastically over the last few years. Give them a shout.