other than swapping over to a v8 and other than the cold air intake,new exhaust,change of gov chip and air filter what can you do to up the horsepower on a v6?

 

Nitrous, cam, torque converter (if it's an auto), and if you have lots of money turbo or supercharger.

You say you want something that adds "horsepower", technically gears don't add hp but they will make your car faster.

 

underdrive pulleys, shift kit (not technically (dont quote me)), ignition upgrade to go with all mentioned above. and last but not least.. type R stickers.

 

change of gov chip, what did you get?

 

All depends on how much you want to spend.

There is SO many options available but the real constraint is time/money and the willingness to dedicate either one to the car.