Questions about adding performance

Hey I have a 2001 chevy silverado 2500 HD 6.0 Liter V8 Gas extended cab. I was wondering what i can add to my truck to add horsepower. What would headers, cold air intake, cat back exauhst do for horsepower? And what websites do you guys recommend for buying parts if you do shop online? thanks for your time

STS Rear Turbos... www.STSturbo.com Thats where you need to go for straight up performance. Although the HD and the 6.0L is a great start, tough parts abound but, that 4L80E tranny is a power sucker. Everything you do short of headers and internal engine mods is going to be minimal improvements at best (IMO). Save up spend the money on a turbo, since you have already have the ultra tough tranny and rear axle, you wouldn't need to beef much else up.

thanks man....keep up the opinions

If you really want perforamce you will need a cam upgrade. CAI, Exhuast will only go so far with stock cam. And you would want to get a new intake manifold for more airflow, and then you would need to get a custom or dyno tune.

still cheaper than a turbo :) but like he said if you REALLY want performance get forced induction.

And Can You Use The Headers (say Pace Setter) From A 5.3 On The 6.0L? I Already Have Dual Exhaust...

Sorry for the delay in updating. I went through this in several stages, and I wanted to provide some measured variables for a good update.

Whell, from 10-11 mpg's up to 13-14 (Combined city/highway).
Here's part of what I did:
1) Replaced Water pump (this one was shot), and both radiator hoses (I still need to replace heater hoses)
2) Replaced both belts (engine and A/C)
3) Replaced BOTH belt tensioners
4) Replaced all idler pulleys left.(I believe there's 2 of them)
5) Alternator was checked and tested OK, so that one stayed, at least for now
6) Put in new tires (265/70/16)
7) Also replaced P/S pump

This seems to have freed engine power a lot.

I still need to replace differential and transmission fluids, as well as the transfer fluid, for a much finer metal contact in the powertrain end of my truck.
Will keep you posted.