You could always build a CAI or FWI. Exhaust will help. You can get 3500 intake too
Well the idea for CAI is more air so why not. The gain wouldnt be too significant. Mitzy's port and polished? I bought a 3500 core engine from the junk yard for $200 delivered (my truck has 2 dry rotted flats) Anyway, if no other mods to the intake you can pick one up at the junkyard for 30 but we're starting to split hairs now. After you would be looking at cam and such for N/A and more speed.