first thing any car will benefit from is a good set of gears. most 3rd gen V6's came with 3.42's, i would up that to a set of 4.10's and install a posi asap.
also, you have a drum brake rear. look around the local salvage yards for a set of aluminum drums. they are easy to spot underneath a variety of gm mid and full size vehicles from teh 60's-80's. tehy are easy to spot, greyish in color, big cooling fins, and round balancing weights. tehy will shed 7-11lbs per side over yoru stock iron drums.
since your car uses teh same style of air intake as teh tpi cars you can do teh free mod on cutting teh bottoms out fo teh filter boxes. the factory put in a big goofy silencer the is not needed as much as teh air it blocks
if you wanna get really tricky you can also fab up a mild ram/cold air set up with a little bit of sheet metal
advnacing your base timing is another nice little free mod taht you will feel with a serious gain in throttle response and a bit more pull throughout teh power band. no need to go nuts, just give it 4-6more degrees of lead and you will like teh results. timing can also be "fixed" with a good custom chip, mail order and off teh shelf junk from fastchips and hypercrap are junk. get the car datalogged and a real chip burned.
the exhaust mods will help, but i would make them teh last priority. work on getting more air into teh engien before you worry about getting it out.
taek a trip over to
www.camarov6.com some time. there are a few 3rd gens running pretty good.
later
tim