Well to go from a stock to a 3.4 or a 3.25 pulley usually nothing is needed. MAF more air more fuel. One thing like i said is the colder plugs with more boost. You can always get a remapped PCM but with basic mods it is not necessary but will help it. With more extensive mods cam heads some other combos it is necessary to get rid of DTC's and to raise rev's and shift points but for the mods i list it is not necessary but can never hurt.......