I've searched on Pep boys perfomance catalog and I saw an aluminum spectre pulley for $40.00. Is this a good pulley for my 02 SSEI? What performance increase can I expect from this pulley or any other one? I'd appreciate any advice.I

what is the size? that is the most important part

I would stick with companies that are really good with 3800s. You can buy single pulleys for 60 bucks from pulleyboys. With a 3.4, you can get a good 25hp gain or so.

Do I need any other modifications in order to swap out pulleys?

you need a pulley puller

www.intense-racing.com check in the pulley section

Underdrive pulley, or supercharger pulley?

Before going with a smaller pulley at least improve the air intake first. Exhaust work is a great improvement but the air intake is enough. Dont just swap the pulley out by itself, the knock retard will take all your power gain from the pulley swap if you do.

Well, it won't take all of your power gain. You will almost always still have a very noticable gain. It just won't be very good for your engine, and you won't have anywhere near as much of a gain as you would with an air intake, plugs, t-stat, exhaust work, etc....

Shawn