The motorcycle carbs, like Webers etc, have no provision for ported vacuum, which is what is required for the distributor. If you draw vacuum for the distributor from the manifold, you will get manifold vacuum at idle to the distributor, when you really want to see none.

Depending on the amount of vacuum, this would mean that you have 100% of the vacuum advance all in at idle when the amount of advance from this source should be zero.

This seems to be the only real disadvantage with these carbs & if you can work your way around it, then you will just love it.