There is also a cast Iron vortec marine intake, that uses 6 individual injectors in each runner, that also has a plastic top (Like the 96 up 4.3 vortecs) and 1 single port throttle body. Every one I saw was painted red in color... I think it was a mercury magnum efi boat engine.... 200 hp + All the new marine 4.3 engines should have the late model vortec head castings on them... carbs on boats should be a thing of the past soon, unless it is two dominators on top of a supercharger, mounted on top of a BBC.... If that zz4.3 ramjet v-6 engine would come out next month as promised by gm... that intake would be awsome on an air-2-air set up and would be the intake to use on the vortec heads...