You'll need a plate between the intake ports and the carb. because the distance between
the intake ports and the carb. throats aren't match. This plate accommodates the coolant
temperature sensor as well. Factory plates are exist, but I don't know how difficult to source them.
Throttle linkage will be needed also between the carbs, and throttle balance also need to
be adjusted correctly between the two sides. The throttle cable is also need to be replaced
in order to match to the different linkage.
The fuel pressure also could be a problem: pressure delivered by the original fuel pump
will overfill the float chambers. So the pressure need to be reduced.