They do come with LSD. I had 3.73 gears installed in mine. I ordered the 3.73 gears combo kit that came with the gears and bearing kit and tuner. It was real simple!
2012 V6 AUTOMATIC 3.7 / MAGNA FLOW MUFFLERS / 3.73 GEARS / STEEDA CAI / 91HYBRID OCTANE TUNE / STRUT BAR / GUNMETAL MATTE METALLIC RACING STRIPE / BBK SHORTY HEADERS / BBK 73MM THROTTLE BODY