I've personally seen some variation between Viggens. Two weeks ago at the Maine Dyno Day, I saw a bone stock Viggen put down ~230hp and ~290 lb. ft. to the front wheels while another one put down ~200hp and ~240 lb. ft. (I'm pulling these from my memory, so my the numbers might be a couple off).
According to BSR, a Stage 2 SS will make 247 hp and 388 nm of torque... calculate a 16% drivetrain loss, which is what most people figure, and you're looking at around 205hp to the front wheels. I have no idea how to convert newton meters to lb. ft... but my whole idea is that variation between Viggens will make it hard to tell the winner. Isn't the SS a heavier car too?