More HP & MPG

I understand that my 89 Tbird, (Standard V6) has only 140 HP and gets an average of 19 MPG. Recently I've replaced the OEM coil with a high performance one, and replaced the OEM air filter with a K&N. I've heard mixed reviews about the K&N filters, should I replace it with the OEM filter? And is there anything that doesnt require major mechanical work that I can do to increase HP, and MPG?? I have also replaced the OEM fan and fan clutch with a flex fan. I was thinking about replacing the flex fan with an electric. But I'm not sure if I will gain any more power or miles/gallon. Any suggestions on how to increase these two aspects of my Bird???

Thanks.

The K & N will give you maybe 3-5 extra HP and give you a 5% increase in fuel mileage; the better you engine can breathe, the more power it can make. Replacing your fan in favor of an electric fan will help with frictional horsepower loss due to a mechanical fan, though you could still lose some power when the alternator has to power up those fans, but that's trivial and negligable. You can even get a little bit of power out of just changing your plugs & wires; also by running synthetic motor oil, it helps reduce the amount of friction in your motor; the only downside to synthetic motor oil, if you have high mileage and have oil leaks, it won't fix those leaks, in fact, you'll go through that oil at a faster rate than conventional oil, not to mention that synthetic is 5xs more expensive than conventional oil & is not compatible, just some things to look for. And last, I know it's over $3 a gallon, but you can run 91 or 93 octane.

thanks theFREAKnasty82 . i posted a thread about higher octane fuel vs lower octane. what i took from the information i got was that since i dont have a high performance or high compression engine, lower octane such as the 89 octane that i use now, would be all that i need. is higher octane more fuel efficient? Also, I begin to notice a my engine shakes just a bit when its warmed up and at idle. its been about a year since i've given my car a complete tune up. Do you think a tune up will stop that little shake? Thanks again..

higher octane fuel usually equals more mpg and hp, dont have to have but would help with desired results ive tested it on mine 87 octane gets 18mpg where amoco 93 gets 26mpg all hiway of course ---plus---- it burns cleaner -less deposits to rob fuel efficiency