The VA116 which I am running duals of and I think is similar to the Corvette fan is pulling near 42A at 13V
Keep in mind that you need to provide at least 13V for the fans to reach full speed. So if your charging system is down the fans will be derated.
And no the fans will not be pulling 84A all the time. With the PWM smart temp sensor they will ramp down unless needed.