If you're not going to drive on the stickies to the track, and you're not running in a specific class that mandates a radial tire, a stick SC will work better on bias-ply drag tires.
Most commonly used are the M/T E-T Street bias ply tires, in the 26.0 x 10.50 x 16" size ... very close in overall dimensions to 255/50/16.
http://www.mickeythompsontires.com/strip.php?item=ETStreet
cheers
Ed N.
The ET Street bias-ply tires will allow you to participate in both DOT and slick-tire events at Gateway International Raceway. I suspect that most tracks will be the same. You would still miss out on a Radial specific class, but I haven't heard of Gateway having one of them.