Chris-
     
     Somewhat tongue-on-cheek, I'll suggest that you only accept advice on 
     wood at the lumberyard.
     
     Don't fiddle with a half-baked solution.  Chuck the duals (apologies 
     to anyone named Charles) and buy a Weber progressive conversion kit.  
     Consists of a complete manifold set (two pair of runners, center 
     plenum, hardware) and a dual stage progressive carb.  The carb is 
     usually "spec'ed" to the application by the importer/seller, but 
     better check.
     
     Used to be these setups cost about $150 new; they're probably more 
     like $250 now.  Fortunately, I've seen several for sale at VW wrecking 
     yards and picked one up for under $100.  It will need a carb rebuild 
     before I install it on my "Project 411", but I can do that.
     
     Somewhere I have a Weber jetting kit that I bought for a reasonable 
     price.  This allowed me to fine tune the carb over time to eliminate 
     hesitation and fouled plugs.  You may want to consider same, if you're 
     mechanically inclined.
     
     The Weber is a little finicky if the incoming fuel pressure is too 
     high.  Most folks who I know who have used the stock VW mechanical 
     pump haven't had problems, but if you use an electric, get a 
     regulator.
     
     Best thing about this system (beyond not having to synch two carbs) is 
     that the complex linkage is eliminated.  Depending on the jetting, the 
     fuel economy may suffer, but performance is usually increased.
     
     BTW, DO NOT USE a 009 distributor on the Type IV engine (this ought to 
     be one of the Ten Commandments).  The advance-at-idle it requires to 
     run the engine at full speed advance will cause serious overheating.  
     I forget the exact number, but the Type IV needs a lot of advance 
     (twenty something, thirty something degrees), but it usually needs to 
     be at or near zero at idle to keep from cooking the heads and pistons. 
      With a little work you can actually use the stock distributor; you 
     just have to find the proper tubes to connect the advance and retard 
     sides of the vacuum unit.
     
     -Blaine