You should be able to get a site on property. The sites with hookups are very expensive and I believe they have a waiting list.
We have stayed in Lot J at least twice. Dry camping. No issues if you go there knowing that and are prepared. The track provides mobil RV pump outs for waste tanks and also has a water truck to fill your RV tank. I think maybe $50 for each. Bring your own drinking water. Also have showers available. There are trailers pulled by pickup trucks that shuttle you from the campground to the track. Works great. I never waited more than 5 minutes for the next shuttle.
It works well. I wouldn't pay for an expensive private campground myself.
RIR is my favorite track. Not too big, not too little. Wish we were going this year, but we're doing the truck race at Eldora and whatever else I can cram in our schedule at last minute.
Try the Chili Bowl in Tulsa sometime. Plan early. Sells out fast.
edit add: RIR website is showing availability in Lot J.
