NHRA Stock class cars don't run screws anymore. I don't run them, and my friends cars don't run them either. We're running 9" slicks, turning 11s with no issues. I have marked the wheel/tire with shoe polish and they haven't budged.
Chuck.
This depends on how hard the car hooks and how much air pressure you run. At 7.5 psi with 14.5 tire on a 15" rim I'm putting screws in it. I just put ten on each side, the spacing is already there just look at the mounting holes.
