01' V6, Whats the best mods to boost HP??

Welcome Aboard! One word supercharger!

three words: nitrous, supercharger, or turbocharger(or a combination of the first and either of the other two!!)

Cheap: underdrive pulley, shifter, gears, tlock,

ok well the Cold air intake gave you about 9. the flows hopefully did no damage (no performance gains on a 6 when switching to dual, usually takes away 1-2 hp). Underdrive pulleys will give you another 8-9, 3.73 gears will give you much more acceleration. from there you can go just about a million different ways with superchargers or turbos or boring out your engine.....there really is no BEST, because it depends realluy on personal preference and what you want the engine/car to do. nitrous is good but dont get too big a shot or youll blow the engine......same with supercharging or turbocharging. both are great but if you use too much boost, your engine wont last long. moderation is the key with the big 3.