Headers are a waste! Sure, the stock parts LOOK like they would really hurt flow, however, people with stock engines seldom see ANY gains by replacing them with aftermarket "shorty" headers. Longtubes are worth something.
Having messed with one of these cars for the past 4 years, here are the BEST bang-the-buck mods I would do if I was starting over. They are listed the order I'd do 'em.
1. Underdrive crank pulley. 75% of the gains of a full 3-pulley system with none of the headaches (charging system problems). Got mine through ASP for ~$40.
2. Gears. 2.73s are just too tall. 3.55s would make a HUGE difference in the "feel" of the car. Mine is an AODE car with 3.27s. IF he had an AODE, I'd say get a Torque converter before or instead of gears. My torque converter gave a better reduction in ET than any other single part I have added.
3. Tuning. 94/95 EECs have a lot of problems with the OEM calibration. Rumor has it that hypertech chips and the like make it worse! Look up a company called "SCT custom tuning". These are the guys that burned my chip, and it worked wonders to help eliminate the part throttle pinging. They also did lots of stuff on the chip to help the AODE work better, but that does not apply in your case.
4. Atfermarket H or X pipe. The OEM 4-cat pipe is the most restrictive part of the exhaust... not the headers, and not the catback. I am running a Magnaflow catted H-pipe (gotta keep the feds happy).
5. Intake manifold! Yes, that's right... intake manifold. The OEM GT lower intake is very restrictive. I am running a ported lower on mine with the stock upper manifold. Gave noticable SOTP gains. The Cobra or Edelbrock Performer manifolds would likely work even better.
6. Heads. Huge gains to be had from aftermarket cylinder heads.
After that, I would then start considering Headers, Throttle Bodies, and MAFs. Honestly, I do not feel that these parts are worth it on a stocker, as the heads and intake are the real bottlenecks.
Tell him NOT to waste his money on any of the Cold Air Intake kits... they are more hype than anything.
My 104k mile car went 14.49 @ 95.2 last November with nothing more than the following mods:
1. Pulley
2. H-pipe
3. Catback (FRPP)
4. Ported lower intake
5. 2600 rpm stall tq. converter
Everything else was 100% stock, including the airbox and paper filter.
Hope this helps.