Just for the sake of being contrary, my Challenger has a cable choke and I had no problem. If it binds, it's likely that it's bound somewhere or dry as a popcorn fart. Take it out, coil it up and put it in a container with oil in it, soak it for a day or two and remove/clean it and put it back in. You can pull the inner cable right out and lube it with Lubriplate as well. I've seen 10 times more grief with automatic chokes than manuals. As for the choke blade of the Holley you already own, there's not a more common carb in the world than Holley and parts, even in Oz, shouldn't be too hard to come by. Food for thought, that's all.