If you are going to run 3 deuces and use Ford's 2 barrel carbs from the 50's, they all had their linkage hook ups on the passenger side. 4 Barrels were on the driver's side. That is the difference.
If I were going to run 3 deuces like what you want to do, I would run the original 55/56 Ford 2 barrel Fordomatic linkage setup and purchase a 3 deuce carb linkage from Honest Charley's or from Speedway motors. Your only issue is going to be your intake manifold... does it have the bosses to bolt down an original 55/56 Ford 2 barrel bellcrank? If not, you will have to rig up something like you are going to do with the 4 barrel bellcrank on the drivers' side. This would mean that you would need longer butterfly shafts for each carb and run your carb linkage from those points on the driver's side.
If you google y block and 3 deuces, you may be able to see some images of what other guys have done.
Daniel JessupLancaster, California
aka "The Hot Rod Reverend" 
check out the 1955 Ford Fairlane build at www.hotrodreverend.com