302 LX Eric has it right.
Make sure the air silencer is out and the car is in good tune. Best bang for the buck is the gears and pulleys and it's a good idea to go with an aftermarket shifter like the Pro 5.0, Hurst, B&M or Steeda Tri-Ax. The next best thing you can do is decide where you want to go with your car, for instance; street, street/strip, full on drag racer, road racer etc. Do you want a quick, but very streetable car, do you want to stay natuarlly aspirated, go supercharged, turbo or nitrous? If you don't have a plan you could end up buying and replacing the same parts several times. Read this board in the Windsor forum and search for topics that you have questions about. About 99.9% of the time several people have asked the same questions you have. Have a blast my man, I hope you know what your getting yourself into!
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91 LX 5.0
Z t-5, 3:73 gear, Vortech 73mm Mass Air, Accufab 65mm TB, BBK underdrives, Crane HI-6S Ignition, BBK unequal length headers, Bassani x pipe, 2.5" Dynomax Super Turbo cat back, Kenny Brown Super Subs, Factory Five Control Arms, Mac cold air kit and more to come!