Since someone suggested a pulley kit, I'm assuming you own an SRT6. If that is indeed the case, you might want to check out code3 performance. They have a pulley that goes on the supercharger rather than the crank and an intake that bolts on right behind the throttle body (not cold air). I did both of these and WOW!

It's not going to give you the most boost of the pulley systems and the intake is a little light on the air cleaning aspect plus it draws in the hot air of the engine compartment. The plus side is that you can almost do it on your budget and you can slap both things on in one hour or less. The intake lets your blower scream like a bancheeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee eeee. Look around the forum and you might find someone selling one or both parts. Start a thread and ask if anyone wants to sell theirs. Someone might want to move up to a 185mm pulley for more bang. You could do that too but it's more bucks and more parts (Gotta change all the pulleys with a 185 but you don't with a Code3)

Wait a minute did you say '04' if it's an '04' it can't be an SRT6 therefore it doesn't have a supercharger therefore forget every thing I just said. Go Needswings!