+1 FTW on the tuner from American Muscle... The K&N CAI is fine, but the JLT CAI develops more power IMO.
Gears and t-lok are not power adders, but they are power MOVERS and should be on your list if you are wanting to make her go quicker.
Long tube headers with no cats or high flow cats will free up some ponies, the shorties like I have are really just for exhaust tone (I like to pretend they are good for a few HP, but I doubt it).
Nitrous or F/I (supercharger) are the big adders, and can be a major investment. If you have ANY serious thought about going Forced Induction or even Nitrous consider replacing the rear end with an 8.8 incher off of a GT, it will handle the added power better than the stock 7.5 inch. This is where I am at right now... Gears and t-lok are on my list for next month when my trip is over and I can't rule out a supercharger in my future so I am rear end shopping rather than the gears and t-lok alone. I can get the gears and t-lok done for $600-$700, I can buy a rear end that alreadt has the gears I want and t-lok for $800-$900 and replace it myself...