[Bad89stang]

Those times sound pretty decent. Were you spinning the tires at all? With practice I would imagine you could get it into the 14's. Your car is basically still stock except for exhaust, pullies and gears.
You could slap on some Gt-40 heads, 1.7RR, and a better intake manifold and get into the 13's. Bump your timing to 14 +/- and see what you end up with.
If you are not on a budget then get some aluminum heads(or ported iron), decent cam, and a matching intake and you will be running very strong.