if the floats drop into the bowl and are not fouled in any way, the ideal height will be 3mm from top of gasket when full of fuel.
i think you need to experiment with the float heights. So to answer your other question, no, the floats would not just drop in without some sort of tang bending. I hope the floats you got are able to do that as some floats are fixed for a particular carb!!
34mm is the venturi nearest the engine.