i would drill and tap the intake at each runner for a wet shot. that will help with even distribution to the cylinders. you will probably will want to re-jet the carbs a little richer and go to a colder spark plug. make sure the fuel system is up to the task also. what kind of pump do you have? do you run a fuel pressure regulator?
i would get it all set up, and then find a dyno that you could test it on to make sure you don't run lean on the spray.
don't try to shoot too much, or that 350 will be towing you home.
