A single injector in each port would work, just program the computer to fire it twice in each 4 stroke cycle. Since the inline six firing order alternates between front and rear cylinders, each injector shot would need to supply enough mixture for only one cylinder. That's also why 3 carburetors work better than two. Each carb of a 3-carb setup only needs to have the volumetric capacity to supply one cylinder. If the 292 has already had the lump port modification, aiming one injector dead center of each port would be an ideal situation.
Jerry
