Best Performance Upgrade

I have a 1993 3.4 liter and i was wondering what would be the best way to upgrade my performance. The engine is stock (as of now). I want a pretty noticeable increase in performance but i don't have the best of money income at the present time. I know that i'm am going to have to spend money to get real upgrades but i can't afford a multi-thousand dollar overhaul as of now. I know of a few ways that i could do this but i need some expert opinions. Anyone? -Also, this is bugging me, will premium gas increase performance of my 3.4 liter engine. I have heard a lot of no's to this question, but what do you all think?

usualy most cars arew designed to run most efficient on the low grade gas the 87. if you start putting higher octane gas in your car when its not required you may develop a bit of a knock. you prob wont really see much of a difference. i suppose if you run premium every now and then just to clean off your injectors and other parts that might develop a build up from cheap gas itd be ok but i dont really recommend putting premium fuel in your car.

as far as the upgrades go. i do recommend ebay to everyone. people make shit at their homes and they sell it for 1/4 the price of stores and its exactly the same so here is a link to ebay for a search on prducts for 1989-1993 grand prix parts. ive seen there are drilled/slotted rotor, speed computer chips, air intakes, by pass puleys and other upgrades pretty cheap it wont hurt to check it out.

http://motors.search.ebay.com/?sofindtype=22&sofocus=bs&fisc=c6028&fmt=6030&fmmk=pontiac&fmmd=grand+prix&fylo=1989&fyhi=1993&satitle=&sadis=500&fpos=60103&fsct=&fsop=1%26fsoo%3D1&fcl=3&frpp=200

I recommend that you do the following for the cheapest way to horsepower. First, cold air intake with a good free flow filter. Next open up the exhaust to allow the car to breathe by installing a bigger down pipe, high flow cat and larger exhaust pipes to free flow mufflers. You can do a lot more but you will spend a lot more money the further you go. Don't waste your money on speed chips from e-bay as they don't really work.

Alright, thanks for the help, i'm going shopping.