The 2006 Chevrolet Silverado 2500HD LS 4dr Extended Cab 4WD SB has a 6.0 L, 300 hp V8 powertrain with standard 5 speed manual transmission.  This trim has 4 doors, seats 6, and offers standard air conditioning, cd player, and ABS brakes.  Power door locks come as an option.  Finally, max towing capacity comes out to 15600 lbs.