My brother recently acquired a Suburban that he put an exhaust in that we'd like to do a slight tune, disable the rear O2s, turn off the EGR, and adjust for bigger tires. It has the 5.7L with the 4L60 and is 4wd. I've tried reading into what options we have and it sounds like the Savanna computer is an option (which he has a 98) or the 411. What exactly are the advantages of the 411 over there Savanna computer? Will either work without issues?