I was wondering if anyone knows of anyone/anywhere I can get underdrive pulleys for my 2001 Monte SS? I only see pulleys sold for the supercharged applications. I have just a 3.8 non supercharged. Thanks in advance!

 

http://www.wbodystore.com/grandprix/...462580616ef4f0

 

So us non-supercharged guys only got the option of an underdrive alternator pulley. I guess thats better than nothing.

 

Are under drive pulleys worth it? How long would it take to pay for itself?
How much HP and increased MPG would I gain by having one on the alternator?

 

Not much. Your better bet would be to actually have someone withing the monte community tune your vehicle for you. Cost about 100 bucks but you can see some better performance and mileage with it.

Other good options are K&N Drop in Air Intake and U-bend delete.