That 2.30 60 foot time is killing you.
A better launch will knock off a tenth, easily. Practice, practice, practice.
Powershifting is also worth a tenth but risky if you mess up. Just watch the tach, shift hard and fast @ 5200 - 5400 RPM on a stock 5.0. A good launch and correct shift points should have you in the 14's with ease.
More:
Try advancing the timing to 14 or 16 degrees.
Free and can be worth a tenth. Easily reversed, too. Use 92 octane (or higher) gas.
Do an oil change and use synthetic oil.
Also worth a tenth.
Like Stangin88 mentioned; A cooled (iced) intake is worth a tenth, too.
Now you're in the mid 14's. See, this was easy! That'll be $10. please.