a cold air intake will add some power.
also look into better spark plugs and spark plug wires.
if you can do without a/c (such as during the winter) get a new belt that doesn't reach the air compressor, the fan and heat will still work.. but keep your old belt where it wont dry rot, it's very easy to put back on
a new battery high performance battery can also add some horsepower by providing more amps/ volts for the spark plugs.
