Mike, the YF's are MUCH easier to tune than the Rochesters; but the W-1's are MUCH easier to tune than the YF's.
Several on these forums, including me, have stated that dual carbs on the stovebolt is difficult, due to the cylinder head port configuration.
The range for duals on the stovebolt is approximately -25 percent (do a poor job with Rochesters) to +10 percent (due a perfect job with W-1's).
If one averages these numbers, the average enthusiast is going to LOSE 7 1/2 percent - thus as Jerry and others have often mentioned: eye candy.
Triple singles, if one can get them to fit in the engine compartment, and are well chosen, can do better.
Where new carburetors (or new lots of other things for that matter) do well is the enthusiast compares the new installation to a worn (badly needing rebuilding) original.
Comparing the performance of a pair of professionally rebuilt Rochester B's is going to be a significant improvement over an original with a stuck power piston, and warped castings. Compare the professionally rebuilt W-1's, to the original, and it really looks like duals are great. But compare apples to apples, not apples to crab apples
(Opinion) Not really a great fan of the way either slotted throttle bodies, or adapters, look. But I don't judge at shows, and never will. To each their own opinion.
Jon.
