Dyno Day.

There is LOTS more in your combo. In my humble opinion, (regarding driveline loss %) your 400whp is around 500 crank.
Even in a heavy a-body, with your gear and good tires, mid to low elevens should be possible. (Wallace says 11.20s). You will need MUCH better tires than cooper cobras at the track. They are a fine street tire, but.......