[rotorwrench]

I am sure that the retard brake will still function with multi carbs but it has to be tuned to the system anytime there is a modification made. The manifold pressure is at its lowest (highest vacuum) when the throttle plates are closed no matter how many there are. With multi carbs, the throttle plates don't have to open as far as a single carb with the same rpm. The carbs do have to have lower setting power valves though so you don't get too much fuel flow during accelleration.

A person can set up a Ford/Mallory ignition to work with it's centrifugal flyweight system only but it can not retard when vacuum drops as the throttle is opened so it won't get as good a fuel milage and could tend to run warmer.