Are you sure that the manifold has not slid forward just a little? There is maybe 1/16 to 1/8" tolerance in the manifold bolt holes. You may need to replace the gaskets if you reposition it.
Otherwise, you could remove the dizzy, plug the hole and tape it off well, use a rat-tail file or rotary bit to grind some clearance into the manifold.
That said - if it is out of position, you will also have a misalignment of the intake ports.