First off, that is a damn good time. The best I could get out of mine was a 13.36 also in terrible conditions with high temps and humidity. The tracks aren't open in my area yet, so I hoping March will see some lower numbers.

Why do think that 400WHP is unattainable? Heck, you can go from 290ish to 320ish with just an intake. Add a custom tune, 185 Pulley, open up the exhaust, port and polish the Supercharger and all intake parts, swap in some colder plugs and that should do it or close to it.