Is the reflash ecm a code from a tuner? or a way to program out the C.A standards? and yes Guido the 3.55 wil get a another MPG,I had two 7.3's and with 3.55 rear ends,no tuners,and no egr system and multiple drivers.The Average MPG was around 20,If it cost ya 500$ to change the gears and your...