What he said, for a good start. And I believe the article was something like '25 tricks to cheap horsepower' or something like that. You can try to google it. Last but not least, just read on this forum very often. And read thread after thread after thread. There are many guys doing a bunch of different setups currently, so once you decide what direction you want to go with the car, you should be able to get lots of good info. Also, even though it's super retarded that ALL years are grouped into one section, you can check out the projects section to see what guys are putting together to meet what goals. Ask questions as the come up, but remember, the search button is your friend.Welcome to the forum!!
There are some things you can do for free to add a few ponies. I don't know your experience level, so I'll start here. Anyhow, there was an old issue of muscle mustangs and fast fords that listed these in the 1990's - maybe you can find it online somewhere if you googled it, or maybe it's on this forum somewhere too. From what i can remember: Make sure the air silencer is removed from the fenderwell, bump the timing to 13-14 degrees if you have access to a timing light and run 93 octane fuel, adjust the throttle position sensor voltage to 0.98 volts at zero throttle and engine key on not running. Make sure your plugs are gapped correctly. Make sure your air filter is clean. Take off you air intake tube and make sure your throttle blade is opening the whole way when the pedal is floored, etc.
If you are looking for the most "seat of the pants" feel, I would start with gears, 3.73 or 4:10's depending on whether you want; just performance 4:10 or a mix of that and highway driving 3:73.
It would be a very good idea to put subframe connectors on it so you don't twist it up. Most people say that's the first mod you should do to any fox body.
Anything to the motor (heads, cam, blower,etc) and you will probably need to convert to mass air.
You could go the heads/cam/intake route if you want to go all motor. You could go nitrous (probably the cheapest up front). I went supercharger just because I've always wanted one. So many options. Just let us know your budget and your goals.
There are many guys on here that know loads more than I do, so just ask.