The standard features of the GMC Sierra 3500HD Base include 6.6L V-8 401hp engine, 6-speed automatic transmission with overdrive, 4-wheel anti-lock brakes (ABS), side seat mounted airbags, curtain 1st row overhead airbag, airbag occupancy sensor, air conditioning, 18" steel wheels, ABS and driveline traction control, StabiliTrak w/Proactive Roll Avoidance electronic stability, AM/FM stereo with 2 speakers.