extra $$$ what to get??

[DemonGT]

in the next 2-4 weeks im not 100% sure but i might be stumpaling across $350 bucks...i was wondering what would be the best investment in the next thing to buy..right now all i have on my car is a K&N,Mac long tubes,off road H and cat back...also keep in mind i could always save a couple bucks from a pay check for something that cost more(example:have $350 save 50/60 bucks for a cobra intake)

tell me what you guys think, also...im not planing on geting $350 and saveing up enough for something like heads or SC...thats to much $$$$, iv got my exhaust done now im thinken of starting on the stuff like mass,TB,intake...would i loss HP with the stock mass and TB and having a cobra intake?(upgrading TB and mass later)

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1991 GT,T-5,air silencer removed,racing clutch(previous owner put in so dont know what kind),K&N air filter,Aiwa deck,power acoustic amp,2 12" pianeers,UPDATE: Just got my Mac long tube headers and Cat-back

By the time summer comes ill have full Mac exhaust,new shifter knob and what ever else i can afford