Slow 5.0?

[Mr 5 0]

90 5.0:

10.9 (16.5) is still pretty slow, as you noted.

On a eighth-mile track, launch and shifting are even more critical than ever, and your stock AOD is at a disadvantage. Lack of experience is also a big factor, as we can all tell you (been there, done that).
Unless you're willing to abuse your tranny big-time and risk an expensive replacement, I would suggest getting a shift kit and consider rear gears (4.10) to see better performance.