Since we are throwing ideas around one that popped in my head was mirroring the valve cover and pump cam shaft for the other head essentially giving each bank of 3 cylinders its own pump. Probably easier just to get a new Raptor intake manifold with port injection. Also, has anyone looked into changing injectors? VW community has been doing for a while. Get an injector from another engine, usually larger displacement, or even a different brand in some cases with a higher flow rate. Bosch apparently makes a majority of the injectors but with different flow rates and spray patterns per the manufacturers request.