as others have stated, you could get the dual quads, and the webers on the 289, and you are correct that it would be a B/FX class car. The previous year Comet were very similar in visuals for both A and B/fx classes so if you look at those youll have an idea on what mods were done. Only 2 A/FX falcons were built. All of this Im sure youre aware of haha