Basically the only power adders you have there is the headers. And without the right tune for them they aren't gettin the full power out of them. The intake is good for 5-8hp, magnaflow is for sound, the throttle body spacer, is a nice paper weight, superchip doesn't do much for you other than change the shift points...

All in all you're not gettin as much as you think. Keep the intake and headers, get rid of the spacer and the superchip. Get a custom tune first. Blackbear performance or a local tuner who uses HPTuners and has a good reputation. A shop with a dyno tune would be best to get the most power out of it. After that get a converter, a hd2 shift kit, ad a transmission cooler to help keep that alive with the new power you're adding. Then throw a cam in there, converter and cam go hand in hand, one helps the other so do some research here. Once you have all that done(intake, headers,converter, cam and tune) next up is a motor swap to a 6.0, or you can do a supercharge/turbo setup. I'd go motor swap, then do the supercharger setup.