what can i install or do to improve power and consequently fuel mileage

Power and fuel mileage, let me know where you find that. These usually have great pwr. and it should get better mpg. May need a tune up, check air filter ect.

(1)Tune -up (2)If it's like mine it really needs a fuel injector cleaner about once a month, minimum every oil change(like a Lucas product works very nice and you notice immediate difference).