The backstretch grandstands were removed after Bruton Smith bought the track in 2007, leaving approximately 31,000 seats, which cover the area from the exit of Turn 4, through the frontstretch and into Turns 1 and 2.
"Two weeks ago I would have told you there was no chance that we could sell out for NASCAR's return," Hillenburg said. "We were doing well two weeks ago but we are doing even better today.
"Sitting here 24 hours before the race, I'm going to say we have a 30 to 40 percent chance of selling out. I already expect a crowd of over 25,000-plus. We are definitely going to rock the house, whether it be 25,000 or 31,000. I'm very excited."
Already this week, NASCAR's return has brought out big crowds for a parade of the NASCAR haulers on Thursday night and an autograph signing and "Thunderfest" festival on Friday night.
"From the hauler parade, we had 'Welcome back NASCAR' signs, I bet I saw over a 100 of them. It was phenomenal," Hillenburg said. "It's all anyone has been talking about - NASCAR's return.
"If I bumped into a pin, I'd probably bust."
