Here’s an iRacing Tour Modified setup for Oxford Plains Speedway 2019 Season 2 with 115° track temperature. This setup was prepared by Old School Racing Motorsports.
This is a quick baseline I made. The fuel should be right and the gear should be very close. The setup is pretty tight to start. Don’t try to run a short gear to get a better pull on exit. You will spin the tires and wear them out quickly on this track. Even with this gear you have to practice a lot of throttle control. Full throttle isn’t really necessary. It’s more important to be very smooth in your transitions.