Back when I was turning wrenches for a living, we did all of our own carb rebuilds. It is not that difficult, at one time I could do a Rochester one barrel in less than 15 minutes, save for the overnight soak in the cleaner. I am not proud of some of the rebuilds we did in that shop, I have learned a lot about linkage and housing wear since then.
You say that your linkage is worn, which is an issue with the Rochester carbs and the linkage design that Chevy used. The pot metal housing of the carb wears fast, and Chevy's linkage placed loads on the carb linkage itself, accelerating the housing wear. This means that a good rebuild of a Rochester carb involves bushing the linkage holes in the housing. Otherwise you do not fix the reason the carb needs rebuilt, the leaks.
The best solution is to find a professional carb rebuilder who does not have an "assembly line" of workers that shoves the carbs out. You need one who treats each carb individually, checks the tolerances and fixes it right. The price is not cheap, but you do end up with a quality product.
For more info on this try visiting Jon's website
http://www.thecarburetorshop.com or searching this forum using his name Carb King.
