The Fuel tap outlets varied with the year. Two outlet types fed the center of each carb pair. Single outlet types fed a "T" fitting. Don't need no stinkin' inline filters if the one inside the tank hasn't been buggared up and is working as Honda intended.
However, if you work in the department of redundancy department, you'll feel soo much better about having multiple filter backups. In that case, use at least three for each carburetor. Gas will be so clean you can eat off it. (Or so I've heard.)