[casper]

Light Beam Placement:
-distance between pre-stage beam and stage beam 7"
-distance between stage beam and gaurd beam 16"
-height of 60' beam 10-10.5"
-height of interval beams,speed trap beams and ET stop beam -all 5-6"

Roll Out - height of beam adjusted as necessary (and possible) to provide 11.5-12" of roll using standard dragster wheel/tire.(22" diam.)
*note , an 11.5" rollout equal on both lanes may not be possible due to track crown. The single most important thing with rollout is that both lanes be as equal as possible.

This info was from a 2004 NHRA Competition Policies & Procedures Manual.

Hope this helps