Found this on the LOR website.

Q: Is camping allowed at Lucas Oil Raceway at Indianapolis during events?
A: Lucas Oil Raceway at Indianapolis offers dry camping for the Chevrolet Performance U.S. Nationals. You can purchase that at the gate or you can reserve your spot early here. For more information about camping at Lucas Oil Raceway please call the office at 317-969-8600.

If you are interested in camping with hook-ups, call Raceview Campgrounds, (317) 852-5737. Also check out their web page, here. Note: Raceview Campgrounds is not affiliated with Lucas Oil Raceway at Indianapolis.

Would give them a call at the 8600 number to see for the track. I know the other campground is VERY close to the track so it would be worth checking out if you for some reason can't camp overnight at the track. Hope that helps!