Fred, Please feel free to add to this if I left anything out. Thanks:thumbsup:The rules on both classes of 1/4 scale will the same as in QSAC rule package. 10.5 plates on both cars. No pin tires on any classes at BMI! We will use the 3" dirt tires on the rear of the SLM because of the amount of work that it would take to make this tire work on a trailing arm car. Up to 4" on right rear of sprint car class. Hope this helps..