I took a look at Roger Kraus Racing's website and they have a PDF with details regarding the RS tire. They are DOT approved (recommended for race track), but the sizes for the RS tire in 15" aren't a good fit for a Cobra.
You could run some SS drag slicks.
http://rogerkrausracing.com/racetire...+2009_2010.pdf
BTW - The date on the PDF is 1//20/10, so they must be fairly new.