suspension, then lower the car, add the intake, increase down pipe size, get a decent exhaust, youll be set for anything passed that.
of course, i dont go buying the most expensive parts for my oldie, but i do think about performance. i was one day looking for an intake for my car, when i realized there was no real intake specifically made for my car, so i had to make it myself.
i bought the correct piping, about 3.5", connected it to my carb air filter, i welded a couple pipes together to position downward to capture cold air.... and voila, i dont even need the cone air filter at the end like most cars do, which means i get more air traveling through the intake piping.
--- this is just something to think about. ive even seen people making their own filters... its crazy to think about, but honestly, it usually works out best if you do research.