I'm looking for some ideas for increasing my horsepower on my 04 5.3 Silverado.

I know my truck is rated at about 295 HP right now stock. Ideally I'd like to try to get another 100-150 HP out of it.

I'm wondering if a K&N filter would work well and if a cold air intake would net much of a difference over just a K&N?

I am wondering about getting a different cat-back exhaust system would work too?

I was thinking of getting a chip or have been looking at the Super Custom Timing Pro (Racers Package) that is due out any time. I am thinking that this tuner package in combination with some Nitrous might do the trick.

What kind of stock pistons does my motor have? Can the motor handle a 100-150 occasional shot of nitrous?

If anyone has any real numbers on the filter, exhaust, tune and nitrous I'd really appreciate it!!!

Thanks,
Dan