Everyone is Correct, your gears have nothing to do with the Trans. I have the 4.10s, Only thing I got done to the Trans, was get the Filter and Fluid changed, and that was only because I was in the shop for work to the car anyway.
07 GT. SCT: CUSTOM TUNE by "MUSTANG SPECIALTIES". LMR: GEN2 2010 STYLE HEADLIGHTS, RAXIOM: 2010 SMOKED COYOTE TAIL LIGHTS, WHEELS: STAGGERED WHL 22X8.5F-22X10R.