Best tire for kart dirt drags?

Gathering opinions on tire options. We run a 233' loose dirt drag strip (think Street Outlaws for karts in the dirt). Most use old race karts with ATV tires.

For the application I use 13x5-6 Carlisle Xtrac tires, and they grip alright.

Would swapping to a Hoosier or Burris grooved 12x8-6 increase or decrease traction? Wider contact patch but much less tread.