#1 Tune up and oil, all fluids, routine maintenance to re-gain old horsepower..
Light weight = fast, so if you can deal with no back seat, a rear seat delete, get rid of spare tire, empty trunk, etc.
Usually people will tell you that you will lose a ton of traction etc, But with your locked rear end and 120 RWHP traction is easy to keep. Ask me how I know, lol
Depending on your money, Get a dual exhaust, CAI, Under drive pulleys, And a tuner and you should see about 20 HP from that depending on the tune and the mileage I would guess.
For every 10% gain in power, It's noticeable driving Horsepower, Keep that in mind.
The 96-98 V6's are rated at 150 Crank horsepower, so to gain enough to really go.. "Hey thats nice.." A tuner is needed, or a port, polish of heads and intake, etc.
Just pick how much you want to spend on it, And get back with us, we will let you know what else to buy. Lol