Alright I'm installing my FRPP 4.10 gears into my 2003 Mustang GT - Automatic next week and I know I have to have my computer reflashed so should I have Ford do this for $60 or should I do it myself with a tuner? I know with the superchip microtuner you have to set your computer back to stock before you go in for any service so if I used that for my 4.10 gears when I went to take my car in for service wouldn't my speedo be off since it's back to stock? And do all tuners require you to take out fuses for fuel, lighter ect to return your car to stock?