First, if you look at any 51-62 factory shop manual it will have a detailed explanation with cutaway drawings as to how the model B carb works. Study it...
Second, if you bottom out the idle screw, you will still have the secondary idle holes located just above the throttle plate that would still be active because you have not plugged the fuel source. It may not be a problem to do this. I would give it a try. You can always go back and plug the passageway later. I'm starting to wonder if it might actually help with minimizing the flat spot you will get when engaging these end carbs... Hmmmm....
Third, the throttle plate has to seal when fully closed or it will surge and idle like crap because there is no longer any idle circuit to add fuel to that air. A vary small amount of air getting past will still work ok, I guess you will know if its good enough or not if you can still affect a change by adjusting the idle mixture on the center carb...
Fourth, remove the power valve. Don't forget to remove the spring loaded ball that the power valve pushes on, or you won't be able to get any fuel past the jet...
Fifth, plug the vac source at the bottom of the carb that activates the power valve.
If you try to engage these modified carbs too soon, you will bog and shudder. I suspect that adding a weighted choke plate similar to the secondaries of a 4bbl Roch. or AFB may help to eliminate this, but I have not had the time to test this theory...
