Considering how frequent Bristol motors were used in FAA aircraft, from the Flycatcher to the Skua and Albacore it's noteworthy that the Hercules never saw much fleet service.
Let's change that. Starting with the Fulmar and Albacore specifications, let's have the FAA demand the Hercules for its aircraft. This will likely have the Swordfish in service longer until the Hercules is ready. And a Fulmar Hercules would be the only single engined fighter thus powered. This presents issues of fighter suitability, though the Beaufighter did fine as a twin.