I don't have the answer for the class, but IMHO it left anything to do with "stock" decades ago. So why call it "Pro Stock"? Why not call it what it is, the "Pro Millionaires Playground"? Run it as a sideline show or at limited events like Pro Mod. Then feature the new Challenger, Camaro and Mustang SS cars. This way at least the new car you see racing on TV looks like the one you see in the showroom.