Joe I did use 3 unisyncs on a 54 corvette a few years ago. Had to borrow 2. But I was looking for some trickey acceloration problem that had me baffeled. I thought 2 carbs were pulling more than the other on acceloration. http://rides.webshots.com/photo/2326100990093759043wLJqQR
But as a normal adjustment process it is just over kill.

I didn't do it, no one saw me do it, you can't prove anything! "Bart Simpson"