Yes, this is the perfect cord to work with the 30471 8000 watt generator. Even though the cord and inlet box have a maximum wattage capacity of 7500 watts, you are still connecting to the 30A outlet on the generator which also has the same 7500 watt max output.
The rule of thumb when sizing a generator it so size it to 80% of the running capacity so the unit has the flexibility to handle starting loads without overloading the generator.
An 8kW unit is the perfect size when connecting to 30A equipment.