1986 5.0 upgrades

[zoobag]

Hi,
This is my first Mustang and I've put a few bucks into her already but nothing major. Just like wheels...some underhood chrome and a Flowmax exhaust...along with a BIG AIR intake with a K&N filter. Otherwise she's pretty much stock.
What I'm wanting to know is if anyone know what upgrades would give me the best bang for my buck....as it were.....
Cash is an issue,(like it is with everyone), so I'm gonna have to limit myself to about $1000 right now....Well that'
s it.
Oh yeah....I've read you can get an additional 18HP JUST by changing the pulleys??!! Is that so?? And how come it's SO HARD to get aftermarket parts for this year ONLY?? Can anyone answer that?
OK...thanks!
Zoobag ~~~^..^~~~