Is there an advantage to losing fuel injection?

Well, one thing that you could do is add this manifold and use EFI throttle bodies that are designed for the IDF bolt pattern and have true electronic fuel injection.

TWM-Throttle Bodies-2930 Series IDF

 

That's a bit of a trick question, because apples-to-apples, (electronic) fuel injection is better than carbs because carbs introduce a pressure drop in order to draw in the fuel (as does CIS somewhat due to the airflow meter); however, CIS injection requires very mild cams in order to minimize pulsations in the intake flow -- i.e.:

if CIS with mild cams = baseline

carbs with mild cams = no better

but with carbs you can use bigger cams = better than CIS with mild cams

8x44mm is a very big carb set-up for a 3L engine -- might make a lot of power at the high end, but idle/low speed operation might not be so great for street use.