If you want alot of performance out of that motor for not a shit load of scratch, I would suggest: volant intake, pacesetter LONG TUBE headers, Y pipe, magnaflow or flowmaster muffler, 160* thermostat, electric fans, 220/220 cam, shift kit, and most importantly a NELSON PERFORMANCE TUNED PCM. I cant stress the tune enough, do not waste your money on absolute shit like hypertech. If you really dont wanna spend much money at all just get the intake, headers, y pipe, muffler, and tune. Just those things will make a HUGE difference.
P.S. This obviously isn't a good site for info on this stuff; for EVERYTHING you'll ever need to know about any mod on your truck go to