Tank Venting
I don't know about Corvettes, but the old Chevelles and the gas filler behind the license plate and if it had a vented cap, gas would come out when accelerating. These tanks had a vent tube that came off the frame ad attached to the floor pan up higher and a non-vented cap. The station wagons and el Caminos had the old conventional gas filler door up higher and these had a vented cap. What the new cars have, might be something similar. I would think that, one way or another, that the tank should be vented. Now, that sure in enlightening.