sure, guys have been cutting off choke bodies and removing plates for a long time in the racing world. That much of a power gain? I don't think so. I'm very very skeptical when it comes to engine performance stuff. Whatever a claimed gain is I always at least cut it in half if not down to 1/3.
The vehicle will no longer have a choke with that setup on their. If the truck is driven much more than in the summer in the best of conditions, forget that idea. For a hot street or race car, sure.