Basically what Pepper said. Expect your truck to be much quicker but don't expect it to be a hot rod and don't expect to outrun the newer Hemis. Without a manifold/head/cam swap, these Magnum engines, with OEM induction, have relatively little power potential. They were designed specifically for low-end torque, a role which they perform well. That doesn't mean that a few bolt-ons, like Pepper cited, aren't beneficial but don't go in with too high of expectations. And in regards to the intake manifold, don't be cheap and try to modify it. You'll gain a miniscule amount of top-end power and lose everything in the low-end, which is where the "kegger" is meant to perform at.