guys i want gears, (3.73) and once all boltons are on i want to be dynotuned. my question is when the guys that do the dyno tune tune the car, they will burn me a custom chip, correct? that will correct the the gears, and air fuel everything else. will ford still be capable to work on the car if need be with a custom chip. will their diagnostic still pick up anything if somthing goes bad? do dyno tuners just reflash factory chip, or new chip? will ford work on either? thanks for any info, sorry so confusing.